com.dahuatech.hutool.http.HttpInputStream Maven / Gradle / Ivy

Go to download
package com.dahuatech.hutool.http;

import com.dahuatech.hutool.core.util.StrUtil;

import java.io.ByteArrayInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.GZIPInputStream;
import java.util.zip.InflaterInputStream;

/**
 * HTTP输入流，此流用于包装Http请求响应内容的流，用于解析各种压缩、分段的响应流内容
 *
 * @author Looly
 */
public class HttpInputStream extends InputStream {

  /** 原始流 */
  private InputStream in;

  /**
   * 构造
   *
   * @param response 响应对象
   */
  public HttpInputStream(HttpResponse response) {
    init(response);
  }

  @Override
  public int read() throws IOException {
    return this.in.read();
  }

  @Override
  public int read(byte[] b, int off, int len) throws IOException {
    return this.in.read(b, off, len);
  }

  @Override
  public long skip(long n) throws IOException {
    return this.in.skip(n);
  }

  @Override
  public int available() throws IOException {
    return this.in.available();
  }

  @Override
  public void close() throws IOException {
    this.in.close();
  }

  @Override
  public synchronized void mark(int readlimit) {
    this.in.mark(readlimit);
  }

  @Override
  public synchronized void reset() throws IOException {
    this.in.reset();
  }

  @Override
  public boolean markSupported() {
    return this.in.markSupported();
  }

  /**
   * 初始化流
   *
   * @param response 响应对象
   */
  private void init(HttpResponse response) {
    try {
      this.in =
          (response.status < HttpStatus.HTTP_BAD_REQUEST)
              ? response.httpConnection.getInputStream()
              : response.httpConnection.getErrorStream();
    } catch (IOException e) {
      if (e instanceof FileNotFoundException) {
        // 服务器无返回内容，忽略之
      } else {
        throw new HttpException(e);
      }
    }

    // 在一些情况下，返回的流为null，此时提供状态码说明
    if (null == this.in) {
      this.in =
          new ByteArrayInputStream(
              StrUtil.format("Error request, response status: {}", response.status).getBytes());
      return;
    }

    if (response.isGzip() && false == (response.in instanceof GZIPInputStream)) {
      // Accept-Encoding: gzip
      try {
        this.in = new GZIPInputStream(this.in);
      } catch (IOException e) {
        // 在类似于Head等方法中无body返回，此时GZIPInputStream构造会出现错误，在此忽略此错误读取普通数据
        // ignore
      }
    } else if (response.isDeflate() && false == (this.in instanceof InflaterInputStream)) {
      // Accept-Encoding: defalte
      this.in = new InflaterInputStream(this.in);
    }
  }
}