Java读取网络数据（新浪网址）InputStream的数据流操作实录笔记（一） 分享出来供大家参考！

package sina.jsontest.test;

import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.JsonParseException;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.ObjectMapper;
public class NetWorkOperator {
	/**
	 * @reference 
	 * 1.<a href="http://www.cnblogs.com/MyFavorite/archive/2010/10/19/1855758.html">http://www.cnblogs.com/MyFavorite/archive/2010/10/19/1855758.html</a><br>
	 * 2.<a href="http://www.blogjava.net/pengpenglin/archive/2008/12/16/220350.html">http://www.blogjava.net/pengpenglin/archive/2008/12/16/220350.html</a><br>
	 * @param args
	 * @throws Exception
	 */
	public static void main(String[] args)throws Exception {
		
		NetWorkOperator kx=new NetWorkOperator();
		String json=kx.getReponse(SinaJsonTest.SinaUrl);
		kx.JSONNodeParse(json);
	}
	/**
	 * <b>获取指定的URL返回的数据信息</b>
	 * @param <font color="#efac10"><a href="http://www.baidu.com">_url:指定的URL</a></font>
	 * @return
	 * @throws ClientProtocolException
	 * @throws IOException
	 */
	public String getReponse(String _url) throws ClientProtocolException, IOException
	{
		String readContent=null;
		DefaultHttpClient httpclient = new DefaultHttpClient();
        HttpGet httpget = new HttpGet(SinaJsonTest.SinaUrl);
        System.out.println("0.Send the URL to Sina Sever....");
        HttpResponse response = httpclient.execute(httpget);
        HttpEntity entity = response.getEntity();

        System.out.println("1.Get Response Status: " + response.getStatusLine());
        if (entity != null) {
            System.out.println("  Get ResponseContentEncoding():"+entity.getContentEncoding());
            System.out.println("  Content Length():"+entity.getContentLength());
            //getResponse
            InputStream in=entity.getContent();
            int count = 0;
            while (count == 0) {
             count = Integer.parseInt(""+entity.getContentLength());//in.available();
            }
            byte[] bytes = new byte[count];
            int readCount = 0; // 已经成功读取的字节的个数
            while (readCount <= count) {
             if(readCount == count)break;
             readCount += in.read(bytes, readCount, count - readCount);
            }
            
            //转换成字符串
            readContent= new String(bytes, 0, readCount, "UTF-8"); // convert to string using bytes

            System.out.println("2.Get Response Content():\n"+readContent);
        }
		return readContent;
	}
	/**
	 * @core 重点用到了readTree方法: 
	 * 1.从文件读取 
	 * ObjectMapper mapper = new ObjectMapper();
	 *       JsonFactory f = new JsonFactory();
	 *       JsonParser jp = f.createJsonParser(new File(fileName)); 
	 *       JsonNode root = mapper.readTree(jp);
	 * 2.从字符串读取
	 *  ObjectMapper mapper = new ObjectMapper(); 
	 *  JsonNode userRootNode = mapper.readTree(json);
	 *  <br/><font color='red'>Java JSON</font>
	 * @param <cite>fileName</cite>=<b>FilePath+FileName</b>
	 */
	public void JSONNodeParse(String json) {
		try {
			ObjectMapper mapper = new ObjectMapper();
			JsonNode root = mapper.readTree(json);
			System.out.println("Source:\n"+root.toString());

			JsonNode userInfoNode = root.path("users").get(0);
			System.out.println("userInfo:" + userInfoNode.toString());// 还可以继续解析
			int next_cursor = root.path("next_cursor").getIntValue();
			System.out.println("next_cursor:" + next_cursor);
			JsonNode previous_cursorNode = root.path("previous_cursor");
			System.out.println("previous_cursorNode:"
					+ previous_cursorNode.getIntValue());

			for (JsonNode node : root.path("users")) {
				System.out.println("Full Entry: " + node.toString());
				// 解析userInfoNode
				String sub_json = node.toString();
				try {
					JsonNode userRootNode = mapper.readTree(sub_json);
					System.out.println("UserRoot Node Size:"+ userRootNode.size());
					Iterator<String> itr = null;
					for (JsonNode _node : userRootNode) {
						itr=_node.getFieldNames();
						//System.out.println("Entry(followers_count): "
						//		+ _node.path("followers_count").getValueAsText());
						while (itr.hasNext()) {
							String fieldName = itr.next();
							if(fieldName.equals("province"))
								System.out.println("province exists!");
							if (_node.path(fieldName).toString().startsWith("\"")
									&& _node.path(fieldName).toString().endsWith("\""))
								System.out.println("Entry("+ fieldName+ "): "
										+ _node.path(fieldName).toString().substring(
										1,_node.path(fieldName).toString().length() - 1));
							else
								System.out.println("Entry(" + fieldName + "): "
										+ _node.path(fieldName).toString());
						}
					}
				} catch (JsonParseException e) {
					e.printStackTrace();
				} catch (JsonMappingException e) {
					e.printStackTrace();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}

		} catch (JsonParseException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

	}

}

用到的 *.jar 包如下：

Eclipse测试通过！分享出来供大家参考。