java利用IO流将内容输出到文本

将网页保存到本地

需要的jar包下载地址
http://download.csdn.net/download/weixin_39549656/10272781

package baike;

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

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class 字符串 {
    public static void main(String[] args) throws Exception, Exception {
        HttpClient client = HttpClients.createDefault();// 创建默认http连接
        HttpPost post = new HttpPost("http://www.qiubaichengren.net/miss/8162.html");// 创建一个get请求
        HttpResponse response = client.execute(post);// 用http连接去执行get请求并且获得http响应

        HttpEntity entity = response.getEntity();// 从response中取到响实体
        ;
        File f = new File("d:\\test.txt");  
        OutputStream out=new FileOutputStream(f);//如果文件不存在会自动创建  
        entity.writeTo(out);
        out.flush();
        out.close();  
    }
}

成功演示

FileOutputStream和OutputStream

public class Test{  
     public static void main(String[] args) throws IOException {  
         File f = new File("d:" + File.separator+"test.txt");  
         OutputStream out=new FileOutputStream(f);//如果文件不存在会自动创建  
         String str="Hello World";  
         byte[] b=str.getBytes();  
         out.write(b);//因为是字节流，所以要转化成字节数组进行输出  
         out.close();  
    }  
 }  

一个字节一个字节进行输出

public class Test {  
public static void main(String[] args) throws IOException {  
File f = new File("d:" + File.separator+"test.txt");  
OutputStream out=new FileOutputStream(f);//如果文件不存在会自动创建  
         String str="Hello World";  
         byte[] b=str.getBytes();  
        for(int i=0;i<b.length;i++){  
            out.write(b[i]);  
         }  
        out.close();  
     }  
 } 

以上输出只会进行覆盖，如果要追加的话，请看FileOutputStream类的另一个构造方法：

public FileOutputStream(File file,boolean append)throws FileNotFoundException

在构造方法中，如果将append的值设置为true，则表示在文件的末尾追加内容。

public class Test11 {  
     public static void main(String[] args) throws IOException {  
         File f = new File("d:" + File.separator+"test.txt");  
         OutputStream out=new FileOutputStream(f,true);//追加内容  
         String str="\r\nHello World";  
         byte[] b=str.getBytes();  
         for(int i=0;i<b.length;i++){  
             out.write(b[i]);  
         }  
         out.close();  
     }  
 }