文件上传
jsp中
<a href="/file/new.action">文件上传案例</a>
fileaction中
@Override
public String execute() throws Exception {
return SUCCESS;
}
配置xml,记得在struts.xml中导入这个xml,
<constant name="struts.multipart.maxSize" value="10485760"/>是修改默认文件上传大小限制
<struts>
<package name="filePackage" extends="basePackage" namespace="/file">
<!--没有method默认调用execute-->
<action name="new" class="com.kaishengit.action.FileAction">
<result>/WEB-INF/views/file/upload.jsp</result>
</action>
<action name="upload" class="com.kaishengit.action.FileAction" method="upload">
<result type="redirectAction">
<param name="actionName">new</param>
<param name="namespace">/file</param>
</result>
</action>
<action name="download" class="com.kaishengit.action.FileAction" method="download">
<result type="stream">
<param name="contentType">${downloadType}</param>
<!--
<param name="contentLength"></param>
-->
<param name="contentDisposition">attachment;filename="${downloadName}"</param>
<param name="inputName">downloadFile</param>
<param name="bufferSize">2048</param>
<param name="allowCaching">true</param>
<param name="contentCharSet">UTF-8</param>
</result>
</action>
</package>
</struts>
跳转到/WEB-INF/views/file/upload.jsp这个jsp中的form表单
action中即使没有doget和dopost方式也要写post提交,但在搜索的时候的form表单中是用get提交
文件上传的时候必须要写enctype="multipart/form-data" 否则用strut2会报错说没有什么input视图
要切记
<form action="/file/upload.action" method="post" enctype="multipart/form-data">
<input type="text" name="title">
<input type="file" name="pic">
<input type="file" name="pic">
<input type="file" name="pic">
<button>保存</button>
</form>
通过配置项来到upload方法中
public String upload() {
/*private File pic;等
记得生成get和set
*/
//System.out.println("Title:" + title);
//这个时候获得的是上传缓存的名字,看不懂
//System.out.println("file:" + pic.getName());
/*这里才是获得文件名字,是使用了约定
private String picFileName
表单file名字+FileName;生成get set*/
//System.out.println("file:" + picFileName);
/*这里才是获得文件类型,是使用了约定
private String picContentType
表单file名字+ContentType;生成get set*/
//System.out.println("type:" + picContentType);
try {
//单文件上传
IOUtils.copy(new FileInputStream(pic), new FileOutputStream(new File("C:/upload",fileName)));
/*多文件上传时
<input type="file" name="pic">
<input type="file" name="pic">
<input type="file" name="pic">
用数组或者集合的形式接收
private List<File> pic;
private List<String> picFileName;
private List<String> picContentType;*/
for(int i = 0;i < pic.size();i++) {
File file = pic.get(i);
String fileName = picFileName.get(i);
IOUtils.copy(new FileInputStream(file), new FileOutputStream(new File("C:/upload",fileName)));
}
} catch (Exception e) {
e.printStackTrace();
}
return SUCCESS;
}
文件下载
方法一:
jsp中
<a href="/file/download.action">下载文件</a>
Fileaction中 获取response
public String download(){
HttpServletResponse response = ServletActionContext.getResponse();
response.setContentType("application/pdf");
OutputStream out = response.getOutputStream();
InputStream in = new FileInputStream(new File("c:/xx.pdf"));
IOUtils.copy(in,out);
out.flush();
out.close();
in.close();
return NONE;
}
可以写在basicAction中,不用每次都写一遍,然后在Fileaction中传入路径即可
public void downloadFile(String filePath) throws Exception{
HttpServletResponse response = ServletActionContext.getResponse();
response.setContentType("application/pdf");
OutputStream out = response.getOutputStream();
InputStream in = new FileInputStream(new File(filePath));
IOUtils.copy(in,out);
out.flush();
out.close();
in.close();
}
但是我们下载的格式不是固定的,可以定义一个map集合,根据后缀名判断
在basicAction中
public static Map<String,String> mimeType = new HashMap<String, String>();
static {
mimeType.put(".pdf", "application/pdf");
mimeType.put(".json", "application/json");
mimeType.put(".doc","application/msword");
mimeType.put(".jpg","image/jpeg");
mimeType.put(".jpeg","image/jpeg");
mimeType.put(".jpe","image/jpeg");
mimeType.put(".xls","application/vnd.ms-excel");
mimeType.put(".zip","application/zip");
mimeType.put(".wps","application/vnd.ms-works");
mimeType.put(".gif","image/gif");
mimeType.put(".mp3","audio/mpeg");
//application/octet-stream
} public void downloadFile(String filePath,String downloadFileName) throws Exception{
HttpServletResponse response = getResponse(); downloadFileName = new String(downloadFileName.getBytes("UTF-8"),"ISO8859-1");
// 设置下载文件的名字
response.addHeader("contentDisposition", "attachment;filename=\""+downloadFileName+"\""); String fileType = filePath.substring(filePath.lastIndexOf("."));
if(mimeType.containsKey(fileType)) {
response.setContentType(mimeType.get(fileType));
} else {
//没有的话就认为是2进制
response.setContentType("application/octet-stream");
} OutputStream out = response.getOutputStream();
InputStream in = new FileInputStream(new File(filePath)); IOUtils.copy(in, out);
out.flush();
out.close();
in.close();
}
方法二
Fileaction中
public String download() throws Exception {
downloadType = "application/pdf";
downloadName = new String("缓存.pdf".getBytes("UTF-8"),"ISO8859-1");
//return了一个success.需要在xml中配置一个返回值是stream
return SUCCESS;
}
public InputStream getDownloadFile() throws Exception {
return new FileInputStream("C:/upload/065-cache.pdf");
}
struts-file.xml中
<action name="download" class="com.kaishengit.action.FileAction" method="download">
<result type="stream">
<param name="contentType">${downloadType}</param>
<!-- 进度条
<param name="contentLength"></param>
-->
<!--下载框--><param name="contentDisposition">attachment;filename="${downloadName}"</param>
<!--给一个输入流,需要在FileAction中配置一个方法获取输入流,返回值是InputStream
方法名为get开头,param里面的参数为去掉get后首字母小写的结果-->
<param name="inputName">downloadFile</param>
<param name="bufferSize">2048</param>
<param name="allowCaching">true</param>
<param name="contentCharSet">UTF-8</param>
</result>
</action>
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这里再讲一个struts中常用的返回形式json
方法1:使用常用的返回方式返回json,首先在pom里添加对gson的导入
public class JSONAction extends BasicAction{
private static final long serialVersionUID = 1L;
@Override
public String execute() throws Exception {
/*在basic中提供renderJSON
public void renderJSON(Object obj) throws Exception {
HttpServletResponse response = getResponse();
response.setContentType("application/json;charset=UTF-8");
Gson gson = new Gson();
String json = gson.toJson(obj);
PrintWriter out = response.getWriter();
out.print(json);
out.flush();
out.close();
}
*/
Map<String, Object> map = new HashMap<String, Object>();
map.put("state", "success");
map.put("result", "OK");
renderJSON(map);
return NONE;
}
}
struts-json中 要继承json-default
<package name="jsonPackage" extends="basePackage,json-default" namespace="/json">
<action name="product" class="com.kaishengit.action.JSONAction"> </action>
</package>
方法2:使用插件返回
导入struts-json-plugin,必须和struts-core的版本一致
public class JSONAction extends BasicAction{
private static final long serialVersionUID = 1L;
private Map<String, Object> map;
@Override
public String execute() throws Exception {
map = new HashMap<String, Object>();
map.put("id", 1001);
map.put("name", "Jerry");
map.put("address", "中国河南省");
return SUCCESS;
}
//get set
public Map<String, Object> getMap() {
return map;
}
public void setMap(Map<String, Object> map) {
this.map = map;
}
}
struts-json中
extends="basePackage,json-default"多继承
<package name="jsonPackage" extends="basePackage,json-default" namespace="/json">
<action name="product" class="com.kaishengit.action.JSONAction">
<!--插件中定义了新的返回值json-->
<result name="success" type="json">
<!--root默认是一个action,会把里面所有的属性都转换成json--
修改成map后只转化里面的map-->
<param name="root">map</param>
<param name="enableGZIP">true</param>压缩,传输快
<param name="noCache">true</param>不缓存
<param name="excludeNullProperties">true</param>排除没有值的属性,不生成json
<param name="contentType">application/JSON</param>
<param name="encoding">UTF-8</param>
</result>
</action>
</package>