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在STRUTS中如何通过request获取从HttpURLConnection写出的流对象

2011-11-10 10:40 627 查看

最近在一个项目中，需要从HttpURLConnection中写出流，在STRUTS中通过request获取流对象，但是，不管怎么样操作，在STRUTS的request中就是不能获取对应的流，很郁闷的说，之后找到了关键点，因为流写出的时候设置了表单提交的形式，导致STRUTS中获取流时出现了问题，struts对没有指定content-type的request请求，封装时候作了一些处理，导致无法在Action中获取request.getInputStream() 和 request.getReader()。详细可以查看代码例子。

1. sendPost方法，从本地中获取流，写入到相应的url链接中：

（重点）：

//需要传递流时，一定要添加的参数，而且ACTION中通过request.getInputStream获取流的情况下，也必须添加该参数

conn.setRequestProperty("content-type", "text/html"); //直接传递流对象

//以下的则是通过form组件的形式来传递流对象的，具体使用上网查看。

conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + java.util.UUID.randomUUID().toString());

public static void main(String[] args) throws UnsupportedEncodingException {

//		String url = "http://61.154.14.46:8080/exter.shtml?serviceType=1011";
String url = "http://localhost:8080/webtest/servlet/URLTest?name=linlin";
//		String url = "http://localhost:8081/exter.shtml?serviceType=1022&menuId=4481&mobile=15806092760&text_data=linlinlin&imgName=testa.jpg";
//		getReturnData1(url);
sendPost(url,null);
}

/**
* 通过HTTP协议以POST形式发送指定文件至指定url
* @param url
* @throws IOException
*/
public static void sendPost(String url,InputStream in) {

HttpURLConnection conn = null;
OutputStreamWriter osw = null;
try {
File file = new File("D:/test2.jpg");
if(!file.exists()) {
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
}
URL url1 = new URL(url);
conn = (HttpURLConnection)url1.openConnection();
conn.setReadTimeout(10000); // 缓存的最长时间
conn.setDoInput(true);// 允许输入
conn.setDoOutput(true);// 允许输出
conn.setUseCaches(false); // 不允许使用缓存
conn.setRequestMethod("POST");
conn.setRequestProperty("Charsert", "UTF-8");
//conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + java.util.UUID.randomUUID().toString());
//需要传递流时，一定要添加的内容，而且ACTION中通过request.getInputStream获取也必须添加该选项
conn.setRequestProperty("content-type", "text/html");
OutputStream o = conn.getOutputStream();
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file));
int BUFFER_SIZE = 1024;
byte[] buf = new byte[BUFFER_SIZE];
int size = 0;
try {
while ((size = bis.read(buf)) != -1)
o.write(buf, 0, size);
} catch (IOException e) {
e.printStackTrace();
}
finally {
try {
bis.close();
o.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

if (conn.getResponseCode() != HttpURLConnection.HTTP_OK)
System.out.println( "connect failed!");
} catch (IOException e) {
e.printStackTrace();
}
finally
{
if (osw != null)
try {
osw.close() ;
} catch (IOException e1) {
e1.printStackTrace();
}

if (conn != null)
conn.disconnect() ;
}
}

2. 当按照以上方法写出流时，就可以在servlet或者action中获取对应的流信息了，代码如下：

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

response.setContentType("text/html");
String s = request.getParameter("name");
System.out.println("s22 is " + s);

InputStream in = request.getInputStream();
if(in != null) {
System.out.println("流不是空的。");
this.writeInputStreamToFile(in);
System.out.println("server time is " + new Date());
} else {
System.out.println("流是空的。");
}

PrintWriter out = response.getWriter();
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println("  <BODY>");
out.print("    This is ");
out.print(this.getClass());
out.println(", using the POST method");
out.println("  </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}

private void writeInputStreamToFile(InputStream in) throws FileNotFoundException {

File file = new File("D:/test3.jpg");
if(!file.exists()) {
try {
file.createNewFile();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

FileOutputStream fos = new FileOutputStream(file);
BufferedInputStream bis = new BufferedInputStream(in);
int BUFFER_SIZE = 1024;
byte[] buf = new byte[BUFFER_SIZE];
int size = 0;
try {
while ((size = bis.read(buf)) != -1)
fos.write(buf, 0, size);
} catch (IOException e) {
e.printStackTrace();
}
finally {
try {
bis.close();
fos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}

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