OutPutStream输出流

忘是亡心i 2022-05-31 14:24 187阅读 0赞

package com.yanshu.controller;  
  
  
import java.io.File;  
import java.io.FileNotFoundException;  
import java.io.FileOutputStream;  
import java.io.IOException;  
import java.io.OutputStream;  
import java.io.PrintWriter;  
import java.io.UnsupportedEncodingException;  
import java.util.Hashtable;  
  
  
import javax.servlet.http.HttpServletResponse;  
  
  
import org.springframework.stereotype.Controller;  
import org.springframework.web.bind.annotation.RequestMapping;  
import org.springframework.web.bind.annotation.RequestMethod;  
  
  
import com.google.zxing.BarcodeFormat;  
import com.google.zxing.EncodeHintType;  
import com.google.zxing.MultiFormatWriter;  
import com.google.zxing.client.j2se.MatrixToImageWriter;  
import com.google.zxing.common.BitMatrix;  
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;  
  
  
import ch.qos.logback.classic.pattern.FileOfCallerConverter;  
  
  
/\*  
 \* 需要的jar包  
 \* <dependency>  
<groupId>com.google.zxing</groupId>  
<artifactId>javase</artifactId>  
<version>1.7</version>  
</dependency>\*/  
/\*\*  
 \* IntputStream  读取  
 \* int read( ); //读取一个字节，返回值为所读的字节   
int read( byte b\[ \] ); //读取多个字节，放置到字节数组b中，通常读取的字节数量为b的长度，返回值为实际读取的字节的数量   
int read( byte b\[ \], int off, int len ); //读取len个字节，放置到以下标off开始字节数组b中，返回值为实际读取的字节的数量   
int available( ); 　　//返回值为流中尚未读取的字节的数量   
long skip( long n )； //读指针跳过n个字节不读，返回值为实际跳过的字节数量   
  
  
 \* outputStream  输出  
 \* ◇ 输出数据：   
void write( int b ); 　　//往流中写一个字节b   
void write( byte b\[ \] ); //往流中写一个字节数组b   
void write( byte b\[ \], int off, int len ); //把字节数组b中从下标off开始，长度为len的字节写入流中   
  
  
◇ flush( ) 　//刷空输出流，并输出所有被缓存的字节，由于某些流支持缓存功能，该方法将把缓存中所有内容强制输出到流中。    
 \* @author 刘瑞光  
 \*  
 \*/  
@Controller  
public class OutPutStreamController \{  
  
@RequestMapping(value="printWriter",method=\{RequestMethod.GET,RequestMethod.POST\})  
public void getPrintWriter(HttpServletResponse response) throws IOException  
\{  
response.setContentType("text/html;charset=utf-8");  
PrintWriter printWriter=response.getWriter();  
printWriter.write("<p>200</p>");  
printWriter.write("<p>PrintWriter</p>");  
printWriter.flush();  
printWriter.close();  
\}  
  
@RequestMapping(value="opstram",method=\{RequestMethod.GET,RequestMethod.POST\})  
public void getStream(HttpServletResponse response) throws IOException  
\{  
String data="天空中飘着云";  
OutputStream outputStream=response.getOutputStream();  
//html :<meta> 标签也能模拟响应头  
outputStream.write("<meta  http-equiv='content-type' content='text/html;charset=utf-8/>".getBytes());  
outputStream.write(data.getBytes("utf-8"));  
outputStream.flush();  
outputStream.close();  
//return outputStream;  
  
\}  
  
  
//http://localhost:8080/health/test  
@RequestMapping(value="/test",method=\{RequestMethod.GET,RequestMethod.POST\})  
public OutputStream getStr(HttpServletResponse response) throws IOException  
\{  
//响应到页面上  
OutputStream outputStream=response.getOutputStream();  
generateQR("22222", 500, 500,outputStream);   
outputStream.flush();  
outputStream.close();  
return outputStream;  
\}  
  
public static void generateQR(String contents, int width, int height, OutputStream os) \{  
Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();  
// 指定纠错等级  
hints.put(EncodeHintType.ERROR\_CORRECTION, ErrorCorrectionLevel.L);  
// 指定编码格式  
//hints.put(EncodeHintType.CHARACTER\_SET, "utf-8");  
try \{  
System.out.println("1----->>>>>>>");  
BitMatrix bitMatrix = new MultiFormatWriter().encode(contents, BarcodeFormat.QR\_CODE, width, height, hints);  
System.out.println("2----->>>>>>>");  
MatrixToImageWriter.writeToStream(bitMatrix, "png", os);  
System.out.println("3----->>>>>>>");  
  
//bitMatrix.  
  
//writeToFile(bitMatrix, "png", new File(imgPath));  
\} catch (Exception e) \{  
e.printStackTrace();  
\}  
\}  
//当个Stream  
public static  void FileAndStream() throws Exception\{  
 File file= new File("d:" + File.separator + "test.txt") ;    // 声明File对象  
 System.err.println(file);  
File f=new File("f://a.txt");//使用File类找到一个文件 文件不存在会自动生成  
OutputStream outputStream=null;//实例化父类对象  
outputStream=new FileOutputStream(f);  
String stringoutPutStream="Hello World!!!";  
byte b\[\]=stringoutPutStream.getBytes();  
outputStream.write(b);//往流中写入一个字节数组\[\]  
outputStream.flush();  
outputStream.close();//关闭输出流  
\}  
//多个stream  
public static void moreFileAndStream() throws Exception  
\{  
File file=new File("f://b.txt");//声明一个File  
OutputStream outputStream=null;  
outputStream=new FileOutputStream(file);//通过对象多态，进行实例化  
String stringOut="Hello World!!! FileOutputStream";//准备一个字符串  
byte b\[\]=stringOut.getBytes();//只能输出byte数组,所以将字符串变为byte  
for(int i=0;i<b.length;i++)//采用循环的方式写入  
\{  
outputStream.write(b\[i\]);//每次只写入一个内容  
\}  
//关闭输出流  
outputStream.close();  
  
\}  
  
public static void addMoreFileAndStream() throws Exception  
\{  
File file=new File("f:"+File.separator+"test.txt");//声明File对象  
OutputStream outputStream=null;//准备好一个输出的对象  
outputStream=new FileOutputStream(file,true);//此出表示文件末尾可以扩展  
String stringOutPutStream="Hellow  sdnskanfmalvavavbag";  
byte b\[\]=stringOutPutStream.getBytes();  
for(int i=0;i<b.length;i++)  
\{  
outputStream.write(b\[i\]);//每次只写入一个内容  
\}  
outputStream.close();  
  
\}  
public static void main(String\[\] args) throws Exception  \{  
 FileAndStream();  
// addMoreFileAndStream();  
\}  
  
  
  
  
\}