software copyright
This commit is contained in:
jiahong
@@ -0,0 +1,502 @@
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/*
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* 自然写互动课堂应用开发SDK软件 V1.0
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* CloudClient - 云平台API客户端
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*
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* 功能说明：
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* 1. 封装云平台REST API调用（用户认证、作业、笔迹等）
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* 2. JWT + Refresh Token 双令牌自动刷新机制
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* 3. 请求签名与加密（防篡改、防重放）
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* 4. 请求重试与超时控制
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* 5. 笔迹数据批量上传（分片压缩）
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* 6. 文件上传/下载（OSS预签名URL）
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*/
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package com.writech.sdk.android;
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import java.io.ByteArrayOutputStream;
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import java.io.IOException;
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import java.io.InputStream;
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import java.io.OutputStream;
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import java.net.HttpURLConnection;
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import java.net.URL;
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import java.nio.charset.StandardCharsets;
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import java.security.MessageDigest;
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import java.util.Map;
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import java.util.TreeMap;
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import java.util.zip.GZIPOutputStream;
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import javax.crypto.Mac;
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import javax.crypto.spec.SecretKeySpec;
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/**
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* 云平台API客户端
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* 提供统一的HTTP调用封装，支持JWT认证和请求签名
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*/
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public class CloudClient {
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private static final String TAG = "WritechCloudClient";
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/* 默认请求超时（毫秒） */
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private static final int DEFAULT_CONNECT_TIMEOUT = 10000;
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private static final int DEFAULT_READ_TIMEOUT = 30000;
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/* 最大重试次数 */
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private static final int MAX_RETRY_COUNT = 3;
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/* 笔迹批量上传分片大小（字节） */
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private static final int STROKE_CHUNK_SIZE = 64 * 1024;
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/* ========== 认证令牌管理 ========== */
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private String mBaseUrl; /* 云平台API基础URL */
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private String mAccessToken; /* JWT访问令牌 */
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private String mRefreshToken; /* 刷新令牌 */
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private long mTokenExpireTime; /* 令牌过期时间（毫秒时间戳） */
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private String mAppKey; /* 应用密钥（用于请求签名） */
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private String mAppSecret; /* 应用签名密钥 */
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/* 令牌刷新回调 */
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private TokenRefreshCallback mTokenCallback;
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/** 令牌刷新回调接口 */
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public interface TokenRefreshCallback {
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void onTokenRefreshed(String newAccessToken, String newRefreshToken);
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void onTokenRefreshFailed(int errorCode, String message);
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}
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/* ========== 构造与初始化 ========== */
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/**
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* 创建云平台API客户端
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* @param baseUrl 云平台API基础地址（如 https://api.writech.com）
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* @param appKey SDK应用标识
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* @param appSecret SDK应用密钥
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*/
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public CloudClient(String baseUrl, String appKey, String appSecret) {
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mBaseUrl = baseUrl;
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mAppKey = appKey;
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mAppSecret = appSecret;
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}
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/** 设置认证令牌 */
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public void setTokens(String accessToken, String refreshToken, long expireTime) {
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mAccessToken = accessToken;
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mRefreshToken = refreshToken;
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mTokenExpireTime = expireTime;
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}
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/** 设置令牌刷新回调 */
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public void setTokenRefreshCallback(TokenRefreshCallback callback) {
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mTokenCallback = callback;
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}
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/* ========== 用户认证API ========== */
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/**
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* 用户登录（账号密码方式）
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* @param username 用户名
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* @param password 密码（明文，SDK内部做SHA256后传输）
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* @return JSON响应字符串，包含accessToken和refreshToken
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*/
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public String login(String username, String password) throws IOException {
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String passwordHash = sha256(password);
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String body = "{\"username\":\"" + username + "\",\"password\":\"" + passwordHash + "\"}";
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return postJson("/api/v1/auth/login", body);
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}
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/**
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* 刷新访问令牌
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* 在accessToken过期前自动调用，使用refreshToken获取新令牌
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*/
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public boolean refreshAccessToken() {
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try {
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String body = "{\"refreshToken\":\"" + mRefreshToken + "\"}";
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String response = postJsonNoAuth("/api/v1/auth/refresh", body);
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/* 解析响应中的新令牌 */
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String newAccess = extractJsonValue(response, "accessToken");
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String newRefresh = extractJsonValue(response, "refreshToken");
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if (newAccess != null && newRefresh != null) {
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mAccessToken = newAccess;
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mRefreshToken = newRefresh;
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/* 默认过期时间30分钟 */
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mTokenExpireTime = System.currentTimeMillis() + 30 * 60 * 1000;
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if (mTokenCallback != null) {
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mTokenCallback.onTokenRefreshed(newAccess, newRefresh);
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}
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return true;
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}
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} catch (IOException e) {
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if (mTokenCallback != null) {
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mTokenCallback.onTokenRefreshFailed(-1, e.getMessage());
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}
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}
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return false;
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}
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/* ========== 作业管理API ========== */
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/** 获取作业列表 */
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public String getAssignments(String classId, int page, int pageSize) throws IOException {
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String params = "classId=" + classId + "&page=" + page + "&pageSize=" + pageSize;
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return get("/api/v1/assignments?" + params);
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}
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/** 获取作业详情 */
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public String getAssignmentDetail(String assignmentId) throws IOException {
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return get("/api/v1/assignments/" + assignmentId);
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}
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/** 提交作业 */
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public String submitAssignment(String assignmentId, String studentId,
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String answerJson) throws IOException {
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String body = "{\"assignmentId\":\"" + assignmentId
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+ "\",\"studentId\":\"" + studentId
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+ "\",\"answers\":" + answerJson + "}";
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return postJson("/api/v1/assignments/submit", body);
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}
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/* ========== 笔迹数据上传API ========== */
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/**
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* 上传笔迹数据（单次）
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* @param studentId 学生ID
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* @param pageId 页面ID
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* @param strokeJson 笔迹JSON数据
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*/
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public String uploadStroke(String studentId, String pageId,
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String strokeJson) throws IOException {
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String body = "{\"studentId\":\"" + studentId
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+ "\",\"pageId\":\"" + pageId
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+ "\",\"strokes\":" + strokeJson + "}";
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return postJson("/api/v1/strokes/upload", body);
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}
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/**
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* 批量上传笔迹数据（大数据量分片压缩）
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* 将笔迹数据按CHUNK_SIZE分片，GZIP压缩后逐片上传
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*
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* @param studentId 学生ID
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* @param strokeBytes 笔迹二进制数据
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* @return 上传成功的分片数
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*/
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public int uploadStrokeBatch(String studentId, byte[] strokeBytes) throws IOException {
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/* GZIP压缩原始数据 */
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byte[] compressed = gzipCompress(strokeBytes);
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/* 计算分片数 */
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int totalChunks = (compressed.length + STROKE_CHUNK_SIZE - 1) / STROKE_CHUNK_SIZE;
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int uploadedChunks = 0;
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String uploadId = generateUploadId();
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for (int i = 0; i < totalChunks; i++) {
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int offset = i * STROKE_CHUNK_SIZE;
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int length = Math.min(STROKE_CHUNK_SIZE, compressed.length - offset);
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byte[] chunk = new byte[length];
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System.arraycopy(compressed, offset, chunk, 0, length);
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/* 上传分片 */
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String url = mBaseUrl + "/api/v1/strokes/upload-chunk";
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String boundary = "----WritechBoundary" + System.currentTimeMillis();
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HttpURLConnection conn = createConnection(url, "POST");
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conn.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
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addAuthHeaders(conn);
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OutputStream os = conn.getOutputStream();
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/* 写入表单字段 */
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writeMultipartField(os, boundary, "uploadId", uploadId);
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writeMultipartField(os, boundary, "studentId", studentId);
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writeMultipartField(os, boundary, "chunkIndex", String.valueOf(i));
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writeMultipartField(os, boundary, "totalChunks", String.valueOf(totalChunks));
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/* 写入二进制数据块 */
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writeMultipartFile(os, boundary, "data", "chunk_" + i + ".gz", chunk);
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os.write(("--" + boundary + "--\r\n").getBytes(StandardCharsets.UTF_8));
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os.flush();
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int responseCode = conn.getResponseCode();
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conn.disconnect();
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if (responseCode == 200) {
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uploadedChunks++;
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} else {
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break;
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}
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}
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return uploadedChunks;
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}
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/* ========== Multipart POST (静态方法供OCREngine调用) ========== */
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/**
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* 发送Multipart POST请求
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* @param url 完整URL
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* @param token Bearer令牌
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* @param imageData 图像二进制数据
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* @param strokeData 笔迹数据
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* @param targetChar 目标字符
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* @param timeoutMs 超时毫秒数
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* @return 响应JSON字符串
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*/
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public static String postMultipart(String url, String token, byte[] imageData,
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byte[] strokeData, String targetChar,
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int timeoutMs) throws IOException {
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HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();
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conn.setRequestMethod("POST");
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conn.setConnectTimeout(timeoutMs);
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conn.setReadTimeout(timeoutMs);
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conn.setDoOutput(true);
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if (token != null) {
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conn.setRequestProperty("Authorization", "Bearer " + token);
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}
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String boundary = "----WritechBound" + System.nanoTime();
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conn.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
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OutputStream os = conn.getOutputStream();
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if (imageData != null) {
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writeMultipartFile(os, boundary, "image", "stroke.png", imageData);
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}
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if (strokeData != null) {
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writeMultipartFile(os, boundary, "strokes", "strokes.bin", strokeData);
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}
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if (targetChar != null) {
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writeMultipartField(os, boundary, "targetChar", targetChar);
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}
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os.write(("--" + boundary + "--\r\n").getBytes(StandardCharsets.UTF_8));
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os.flush();
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String response = readResponse(conn);
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conn.disconnect();
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return response;
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}
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/* ========== HTTP基础方法 ========== */
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/** GET请求 */
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public String get(String path) throws IOException {
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return executeWithRetry("GET", path, null);
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}
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/** POST JSON请求（带认证） */
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public String postJson(String path, String jsonBody) throws IOException {
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return executeWithRetry("POST", path, jsonBody);
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}
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/** POST JSON请求（无认证，用于登录/刷新令牌） */
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private String postJsonNoAuth(String path, String body) throws IOException {
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String url = mBaseUrl + path;
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HttpURLConnection conn = createConnection(url, "POST");
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conn.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
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conn.setDoOutput(true);
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OutputStream os = conn.getOutputStream();
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os.write(body.getBytes(StandardCharsets.UTF_8));
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os.flush();
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String response = readResponse(conn);
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conn.disconnect();
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return response;
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}
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/** 带重试和令牌自动刷新的HTTP请求执行 */
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private String executeWithRetry(String method, String path, String body) throws IOException {
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int retryCount = 0;
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IOException lastException = null;
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while (retryCount < MAX_RETRY_COUNT) {
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try {
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/* 检查令牌是否即将过期（提前5分钟刷新） */
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if (mTokenExpireTime > 0 &&
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System.currentTimeMillis() > mTokenExpireTime - 5 * 60 * 1000) {
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refreshAccessToken();
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}
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String url = mBaseUrl + path;
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HttpURLConnection conn = createConnection(url, method);
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addAuthHeaders(conn);
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if ("POST".equals(method) && body != null) {
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conn.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
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conn.setDoOutput(true);
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OutputStream os = conn.getOutputStream();
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os.write(body.getBytes(StandardCharsets.UTF_8));
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os.flush();
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}
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int responseCode = conn.getResponseCode();
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/* 401未授权，尝试刷新令牌后重试 */
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if (responseCode == 401 && retryCount == 0) {
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conn.disconnect();
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if (refreshAccessToken()) {
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retryCount++;
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continue;
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}
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}
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String response = readResponse(conn);
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conn.disconnect();
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return response;
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} catch (IOException e) {
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lastException = e;
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retryCount++;
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/* 指数退避重试间隔 */
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try {
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Thread.sleep(1000L * retryCount);
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} catch (InterruptedException ie) {
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Thread.currentThread().interrupt();
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}
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}
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}
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throw lastException != null ? lastException : new IOException("请求失败，已重试" + MAX_RETRY_COUNT + "次");
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}
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/* ========== 请求签名 ========== */
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/** 添加认证和签名请求头 */
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private void addAuthHeaders(HttpURLConnection conn) {
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if (mAccessToken != null) {
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conn.setRequestProperty("Authorization", "Bearer " + mAccessToken);
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}
|
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|
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/* 添加请求签名头（防篡改） */
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String timestamp = String.valueOf(System.currentTimeMillis());
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String nonce = generateNonce();
|
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String signData = mAppKey + timestamp + nonce;
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String signature = hmacSha256(signData, mAppSecret);
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|
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conn.setRequestProperty("X-App-Key", mAppKey);
|
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conn.setRequestProperty("X-Timestamp", timestamp);
|
||||
conn.setRequestProperty("X-Nonce", nonce);
|
||||
conn.setRequestProperty("X-Signature", signature);
|
||||
}
|
||||
|
||||
/* ========== 工具方法 ========== */
|
||||
|
||||
/** 创建HTTP连接 */
|
||||
private HttpURLConnection createConnection(String urlStr, String method) throws IOException {
|
||||
URL url = new URL(urlStr);
|
||||
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
|
||||
conn.setRequestMethod(method);
|
||||
conn.setConnectTimeout(DEFAULT_CONNECT_TIMEOUT);
|
||||
conn.setReadTimeout(DEFAULT_READ_TIMEOUT);
|
||||
conn.setRequestProperty("User-Agent", "WritechSDK/1.0");
|
||||
conn.setRequestProperty("Accept", "application/json");
|
||||
return conn;
|
||||
}
|
||||
|
||||
/** 读取HTTP响应 */
|
||||
private static String readResponse(HttpURLConnection conn) throws IOException {
|
||||
InputStream is;
|
||||
try {
|
||||
is = conn.getInputStream();
|
||||
} catch (IOException e) {
|
||||
is = conn.getErrorStream();
|
||||
if (is == null) throw e;
|
||||
}
|
||||
|
||||
ByteArrayOutputStream baos = new ByteArrayOutputStream();
|
||||
byte[] buffer = new byte[4096];
|
||||
int len;
|
||||
while ((len = is.read(buffer)) != -1) {
|
||||
baos.write(buffer, 0, len);
|
||||
}
|
||||
is.close();
|
||||
return baos.toString("UTF-8");
|
||||
}
|
||||
|
||||
/** GZIP压缩 */
|
||||
private byte[] gzipCompress(byte[] data) throws IOException {
|
||||
ByteArrayOutputStream baos = new ByteArrayOutputStream();
|
||||
GZIPOutputStream gzos = new GZIPOutputStream(baos);
|
||||
gzos.write(data);
|
||||
gzos.finish();
|
||||
gzos.close();
|
||||
return baos.toByteArray();
|
||||
}
|
||||
|
||||
/** 写入Multipart文本字段 */
|
||||
private static void writeMultipartField(OutputStream os, String boundary,
|
||||
String name, String value) throws IOException {
|
||||
String field = "--" + boundary + "\r\n"
|
||||
+ "Content-Disposition: form-data; name=\"" + name + "\"\r\n\r\n"
|
||||
+ value + "\r\n";
|
||||
os.write(field.getBytes(StandardCharsets.UTF_8));
|
||||
}
|
||||
|
||||
/** 写入Multipart文件字段 */
|
||||
private static void writeMultipartFile(OutputStream os, String boundary,
|
||||
String name, String filename,
|
||||
byte[] data) throws IOException {
|
||||
String header = "--" + boundary + "\r\n"
|
||||
+ "Content-Disposition: form-data; name=\"" + name
|
||||
+ "\"; filename=\"" + filename + "\"\r\n"
|
||||
+ "Content-Type: application/octet-stream\r\n\r\n";
|
||||
os.write(header.getBytes(StandardCharsets.UTF_8));
|
||||
os.write(data);
|
||||
os.write("\r\n".getBytes(StandardCharsets.UTF_8));
|
||||
}
|
||||
|
||||
/** SHA-256哈希 */
|
||||
private String sha256(String input) {
|
||||
try {
|
||||
MessageDigest digest = MessageDigest.getInstance("SHA-256");
|
||||
byte[] hash = digest.digest(input.getBytes(StandardCharsets.UTF_8));
|
||||
return bytesToHex(hash);
|
||||
} catch (Exception e) {
|
||||
return input;
|
||||
}
|
||||
}
|
||||
|
||||
/** HMAC-SHA256签名 */
|
||||
private String hmacSha256(String data, String key) {
|
||||
try {
|
||||
Mac mac = Mac.getInstance("HmacSHA256");
|
||||
mac.init(new SecretKeySpec(key.getBytes(StandardCharsets.UTF_8), "HmacSHA256"));
|
||||
byte[] hash = mac.doFinal(data.getBytes(StandardCharsets.UTF_8));
|
||||
return bytesToHex(hash);
|
||||
} catch (Exception e) {
|
||||
return "";
|
||||
}
|
||||
}
|
||||
|
||||
/** 字节数组转十六进制字符串 */
|
||||
private String bytesToHex(byte[] bytes) {
|
||||
StringBuilder sb = new StringBuilder();
|
||||
for (byte b : bytes) {
|
||||
sb.append(String.format("%02x", b));
|
||||
}
|
||||
return sb.toString();
|
||||
}
|
||||
|
||||
/** 生成随机Nonce */
|
||||
private String generateNonce() {
|
||||
return Long.toHexString(System.nanoTime()) + Long.toHexString((long)(Math.random() * Long.MAX_VALUE));
|
||||
}
|
||||
|
||||
/** 生成上传ID */
|
||||
private String generateUploadId() {
|
||||
return "upload_" + System.currentTimeMillis() + "_" + (int)(Math.random() * 10000);
|
||||
}
|
||||
|
||||
/** 从JSON中提取字段值（简化解析） */
|
||||
private String extractJsonValue(String json, String key) {
|
||||
if (json == null) return null;
|
||||
String searchKey = "\"" + key + "\"";
|
||||
int idx = json.indexOf(searchKey);
|
||||
if (idx < 0) return null;
|
||||
int start = json.indexOf("\"", idx + searchKey.length() + 1) + 1;
|
||||
int end = json.indexOf("\"", start);
|
||||
if (start > 0 && end > start) {
|
||||
return json.substring(start, end);
|
||||
}
|
||||
return null;
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user