成功代码:
前台界面jsp: <a style="text-decoration:none;" href="<%=path %>/main/frontNewsAction_downloadFile.action?fileName=<s:property value="fileTitle"/>">下载</a> Action文件:
private String fileName;//get set方法
public String getDownloadFileName() {
String downFileName = fileName;
try {
downFileName = new String(downFileName.getBytes(), "utf-8");
} catch (Exception e) {
e.printStackTrace();
}
return downFileName;
} //下载的流
public InputStream getInputStream() throws FileNotFoundException {
String name=this.getDownloadFileName();
File file = new File(ServletActionContext.getServletContext().getRealPath("/file")+"/"+name);
InputStream inputStream = new FileInputStream(file);
return new FileInputStream(file);
} // 下载
public String downloadFile() throws Exception {
return "downloadFile";
}
<!-- 文件下载 -->
<result name="downloadFile" type="stream">
<param name="contentType">
application/octet-stream;charset=utf-8
</param>
<param name="contentDisposition">
attachment;filename="${downloadFileName}"
</param>
<param name="inputName">inputStream</param>
<param name="bufferSize">4096</param>
</result>
出现错误时是由于在action中的public InputStream getInputStream()方法返回值为:return ServletActionContext.getServletContext().getResourceAsStream(ServletActionContext.getServletContext().getRealPath("/file")+"/"+name);
造成的异常
学习内容:
配置文件:
<!-- 文件下载,支持中文附件名 -->
<action name="fileDownload"
class="com.test.action.filedown.FileDownloadAction">
<result name="success" type="stream">
<!--
动态文件下载的,事先并不知道未来的文件类型,那么我们可以把它的值设置成为:application/octet-
stream;charset=ISO8859-1 ,注意一定要加入charset,否则某些时候会导致下载的文件出错; -->
<param name="contentType">
application/octet-stream;charset=ISO8859-1
</param>
<param name="contentDisposition">
<!-- 使用经过转码的文件名作为下载文件名,downloadFileName属性
对应action类中的方法 getDownloadFileName()
其中特殊的代码就是${downloadFileName},它的效果相当于运行的时候将action对象的属性的取值动态的填充在${}中间的部分,我
们可以认为它等价于+action. getDownloadFileName()。 -->
attachment;filename="${downloadFileName}"
</param>
<param name="inputName">inputStream</param>
<param name="bufferSize">4096</param>
</result>
</action>
action文件:
----------------------------------------------------------
action中
----------------------------------------------------------
private String fileName;// 初始的通过param指定的文件名属性 set get
/** 文件名 转换编码 防止中文乱码*/
public String getDownloadFileName() {
String fileName=ServletActionContext.getRequest().getParameter("fileName");
String downFileName = fileName;
try {
downFileName = new String(downFileName.getBytes(), "ISO8859-1");
} catch (Exception e) {
e.printStackTrace();
}
return downFileName;
}
//下载的流
public InputStream getInputStream() {
String name=this.getDownloadFileName();
// String realPath=ServletActionContext.getServletContext().getRealPath("/uploadImages")+ "/"+name; 路径错误
String realPath="/uploadImages/"+name;
InputStream in=ServletActionContext.getServletContext().getResourceAsStream(realPath);
if(null==in){
System.out.println("Can not find a java.io.InputStream with the name
[inputStream] in the invocation stack. Check the <param
name=\"inputName\"> tag specified for this
action.检查action中文件下载路径是否正确.");
}
return ServletActionContext.getServletContext().getResourceAsStream(realPath);//出现异常
}
@Override
public String execute() throws Exception {
return SUCCESS;
}