httpclient post 文件下载工具类

以下是一个使用 HttpClient 进行文件下载的工具类示例：

import org.apache.http.HttpEntity;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.apache.http.util.EntityUtils;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

public class FileDownloadUtil {

    private static final int TIMEOUT_CONNECTION = 5000; // 连接超时时间
    private static final int TIMEOUT_SOCKET = 5000; // 读取超时时间

    public static boolean downloadFile(String url, String filePath) {
        HttpClient httpClient = null;
        HttpGet httpGet = null;
        try {
            httpClient = getHttpClient();
            httpGet = new HttpGet(url);
            HttpEntity httpEntity = httpClient.execute(httpGet).getEntity();
            if (httpEntity != null) {
                FileOutputStream fos = new FileOutputStream(new File(filePath), false);
                fos.write(EntityUtils.toByteArray(httpEntity));
                fos.flush();
                fos.close();
                return true;
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (httpGet != null) {
                httpGet.abort();
            }
            if (httpClient != null) {
                ClientConnectionManager mgr = httpClient.getConnectionManager();
                if (mgr != null) {
                    mgr.shutdown();
                }
            }
        }
        return false;
    }

    private static HttpClient getHttpClient() {
        HttpParams params = new BasicHttpParams();
        HttpConnectionParams.setConnectionTimeout(params, TIMEOUT_CONNECTION);
        HttpConnectionParams.setSoTimeout(params, TIMEOUT_SOCKET);
        return new DefaultHttpClient(params);
    }
}

使用示例：

String url = "http://example.com/example.pdf";
String filePath = "/path/to/file/example.pdf";
boolean success = FileDownloadUtil.downloadFile(url, filePath);
if (success) {
    System.out.println("文件下载成功！");
} else {
    System.out.println("文件下载失败！");
}

需要注意的是，在使用 HttpClient 进行网络请求时，需要在 AndroidManifest.xml 文件中添加网络访问权限：

<uses-permission android:name="android.permission.INTERNET" />