在某些特殊情况下，需要获取HttpPost对象中的参数，demo如下

public static HttpResponse test( HttpPost post ) throws IOException{                /**         * 入参是HttpPost，在该方法中想根据HttpPost中的参数做一些逻辑，这时候就需要想办法获取到HttpPost中的入参         */        HttpEntity entity = post.getEntity();      //代码一        //      InputStream inputStream = entity.getContent();      //方法一//      System.out.println(EntityUtils.toString(entity));   //方法二        //获取入参的方法        MyHttpEntityUnil.test(entity);   //方法三                HttpClient httpclient = new DefaultHttpClient();        return httpclient.execute(post);    }    public static void main(String[] args) throws ParseException, IOException {                ContentType contentType = ContentType.create("text/plain", Consts.UTF_8);        MultipartEntityBuilder builder = MultipartEntityBuilder.create();                builder.addTextBody("aaa", "bbb", contentType);                HttpEntity requestEntity = builder.build();                HttpPost post = new HttpPost("http://127.0.0.1:8080/index");        post.setEntity(requestEntity);                test(post);            }

常规思路如demo中的方法一、方法二都是通过获取HttpEntity的输入流（InputStream），但是会抛一个异常，原因是该处使用的HttpEntity是实现类MultipartFormEntity，而MultipartFormEntity并没有实现接口HttpEntity的getContent()方法。这时候就要转变思路，查看MultipartFormEntity的源码，如下

/* * ==================================================================== * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements.  See the NOTICE file * distributed with this work for additional information * regarding copyright ownership.  The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License.  You may obtain a copy of the License at * *   http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied.  See the License for the * specific language governing permissions and limitations * under the License. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation.  For more * information on the Apache Software Foundation, please see * 
    . * */package org.apache.http.entity.mime;import org.apache.http.Header;import org.apache.http.HttpEntity;import org.apache.http.message.BasicHeader;import org.apache.http.protocol.HTTP;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;class MultipartFormEntity implements HttpEntity {    private final AbstractMultipartForm multipart;    private final Header contentType;    private final long contentLength;    MultipartFormEntity(            final AbstractMultipartForm multipart,            final String contentType,            final long contentLength) {        super();        this.multipart = multipart;        this.contentType = new BasicHeader(HTTP.CONTENT_TYPE, contentType);        this.contentLength = contentLength;    }    AbstractMultipartForm getMultipart() {        return this.multipart;    }    public boolean isRepeatable() {        return this.contentLength != -1;    }    public boolean isChunked() {        return !isRepeatable();    }    public boolean isStreaming() {        return !isRepeatable();    }    public long getContentLength() {        return this.contentLength;    }    public Header getContentType() {        return this.contentType;    }    public Header getContentEncoding() {        return null;    }    public void consumeContent()        throws IOException, UnsupportedOperationException{        if (isStreaming()) {            throw new UnsupportedOperationException(                    "Streaming entity does not implement #consumeContent()");        }    }    public InputStream getContent() throws IOException {        throw new UnsupportedOperationException(                    "Multipart form entity does not implement #getContent()");    }    public void writeTo(final OutputStream outstream) throws IOException {        this.multipart.writeTo(outstream);    }}

通过查看源码可以发现，其实数据是保存在私有属性AbstractMultipartForm中的，并且有一个getMultipart()方法可以获取该属性，但是该方法只能同包下使用，所以新建一个相同路径的包，在该包下调用getMultipart()方法。代码如下

package org.apache.http.entity.mime;import java.io.IOException;import java.io.Reader;import java.util.List;import org.apache.http.HttpEntity;import org.apache.http.entity.mime.content.StringBody;public class MyHttpEntityUnil {    public static void test( HttpEntity entity ) throws IOException{        List
    
      bodyParts = ((MultipartFormEntity)entity).getMultipart().getBodyParts();        for( FormBodyPart bodyPart : bodyParts ){            String name = bodyPart.getName();            System.out.println(name);            StringBody body = (StringBody) bodyPart.getBody();            Reader reader = body.getReader();            char[] cs = new char[1024];            reader.read(cs);                        System.out.println(new String(cs));        }    }    }