为什么这段代码无法显示图片啊
import java.io.IOException;import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import com.sun.image.codec.jpeg.*;//sun公司仅提供了jpg图片文件的编码api
import javax.imageio.stream.*;
import java.awt.*;
import java.awt.image.BufferedImage;
/**
*
* 显示文件的Servlet
* 负责从本地文件中读取图片，
*
*/
public class ShowPic extends javax.servlet.http.HttpServlet implements
javax.servlet.Servlet {
private static final String GIF = "image/gif;charset=GB2312";// 设定输出的类型
private static final String JPG = "image/jpeg;charset=GB2312";
/*
* (non-Java-doc)
*
* @see javax.servlet.http.HttpServlet#HttpServlet()
*/
public ShowPic() {
super();
}
/*
* (non-Java-doc)
*
* @see javax.servlet.http.HttpServlet#doGet(HttpServletRequest request,
* HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
/*
* (non-Java-doc)
*
* @see javax.servlet.http.HttpServlet#doPost(HttpServletRequest request,
* HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
String spec = request.getParameter("spec");// 输出图片的类型的标志
String imagePath = "D:\\temp\\1.jpg";
response.reset();
OutputStream output = response.getOutputStream();// 得到输出流
if (imagePath.toLowerCase().endsWith(".jpg"))// 使用编码处理文件流的情况：
{
response.setContentType(JPG);// 设定输出的类型
// 得到图片的真实路径
// 得到图片的文件流
InputStream imageIn = new FileInputStream(new File(imagePath));
// 得到输入的编码器，将文件流进行jpg格式编码
JPEGImageDecoder decoder = JPEGCodec.createJPEGDecoder(imageIn);
// 得到编码后的图片对象
BufferedImage image = decoder.decodeAsBufferedImage();
// 得到输出的编码器
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(output);
encoder.encode(image);// 对图片进行输出编码
imageIn.close();// 关闭文件流
}
if (imagePath.toLowerCase().endsWith(".gif"))// 不使用编码处理文件流的情况：
{
response.setContentType(GIF);
ServletContext context = getServletContext();// 得到背景对象
InputStream imageIn = context.getResourceAsStream(imagePath);// 文件流
BufferedInputStream bis = new BufferedInputStream(imageIn);// 输入缓冲流
BufferedOutputStream bos = new BufferedOutputStream(output);// 输出缓冲流
byte data[] = new byte[4096];// 缓冲字节数
int size = 0;
size = bis.read(data);
while (size != -1) {
bos.write(data, 0, size);
size = bis.read(data);
}
bis.close();
bos.flush();// 清空输出缓冲流
bos.close();
}
output.close();
}
}
<servlet>
<servlet-name>ShowPic</servlet-name>
<display-name>ShowPic</display-name>
<description></description>
<servlet-class>
cn.ccb.zlgz.web.servlet.ShowPic</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ShowPic</servlet-name>
<url-pattern>/ShowPic</url-pattern>
</servlet-mapping>
Html代码
<html>
<body>
<img src="ShowPic?spec=2"></a>
</body>
</html>
http://tntxia.iteye.com/blog/826193源地址。
--------------------编程问答-------------------- 你设置一个断点，看有没有进入你的Servlet中，有报错吗？没有报错说明你配置的路径不对 --------------------编程问答-------------------- java.io.IOException: Stream closed
at java.io.BufferedInputStream.getInIfOpen(Unknown Source)
at java.io.BufferedInputStream.fill(Unknown Source)
at java.io.BufferedInputStream.read1(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
at java.io.FilterInputStream.read(Unknown Source)
at max.tool.ShowPic.doPost(ShowPic.java:88)
at max.tool.ShowPic.doGet(ShowPic.java:45)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at max.com.ModifyCode.doFilter(ModifyCode.java:23)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:186)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
at java.lang.Thread.run(Unknown Source) --------------------编程问答-------------------- <servlet>
<servlet-name>ShowPic</servlet-name>
<display-name>ShowPic</display-name> <description></description>
<servlet-class>
max.tool.ShowPic</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ShowPic</servlet-name>
<url-pattern>/ShowPic</url-pattern>
</servlet-mapping>
</web-app>
这里也报错啊。。 --------------------编程问答-------------------- 路径还是max.tool.ShowPic这个把。。没有什么报错咯
补充：Java , Java相关
