/**
* 下载文件
* @param filePath --文件完整路径
* @param response --HttpServletResponse对象
*/
public static void downloadFile(
String filePath,
javax.servlet.http.HttpServletResponse response) {
String fileName = ""; //文件名，输出到用户的下载对话框
//从文件完整路径中提取文件名，并进行编码转换，防止不能正确显示中文名
try {
if(filePath.lastIndexOf("/") > 0) {
fileName = new String(filePath.substring(filePath.lastIndexOf("/")+1, filePath.length()).getBytes("GB2312"), "ISO8859_1");
}else if(filePath.lastIndexOf("\\") > 0) {
fileName = new String(filePath.substring(filePath.lastIndexOf("\\")+1, filePath.length()).getBytes("GB2312"), "ISO8859_1");
}
}catch(Exception e) {}
//打开指定文件的流信息
FileInputStream fs = null;
try {
fs = new FileInputStream(new File(filePath));
}catch(FileNotFoundException e) {
e.printStackTrace();
return;
}
//设置响应头和保存文件名
response.setContentType("APPLICATION/OCTET-STREAM");
response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
//写出流信息
int b = 0;
try {
PrintWriter out = response.getWriter();
while((b=fs.read())!=-1) {
out.write(b);
}
fs.close();
out.close();
System.out.println("文件下载完毕.");
}catch(Exception e) {
e.printStackTrace();
System.out.println("下载文件失败!");
}
}
方法在表现层里调用，比如Struts或Servlet里。
用java提供的api实现从证书文件(本实例实验对象为*.cer文件)中获取有效信息的方法..
public static X509Certificate getCert(String fileName) throws Exception {//从一个有效的证书文件来创建证书..
InputStream inStream = new FileInputStream(fileName);
CertificateFactory cf = CertificateFactory.get ......
需要dom4j.jar文件 ，自行下载。 test.xml 1: <?xml version="1.0" encoding="gbk"?>
2:
3: <students>
4: <person sex="男" age="21">
5: <id>1</id>
6: <name>章治鹏</name>
7: <homepage&g ......
