ExtJs+Jersey上传文件

当使用ExtJs默认提供的上传方法与Jersey一块使用的时候碰到了两个头疼的问题，在此记下来给大家提个醒。

主要有两个地方要注意

1.当使用ExtJs表单提交到Jersey服务端端上传文件的时候，服务端代码要设置成

@Produces(MediaType.TEXT_HTML)

否则在前台ExtJs转化Json对象的时候会报

uncaught exception: You're trying to decode an invalid JSON String: <pre>{"success":true,"errorCode":-1,"error":""}</pre

参考：http://stackoverflow.com/questions/9716694/have-issue-with-response-of-submit-in-extjs-response-in-json-but-somewhere-html

2.ExtJs回执事件每次都到failure，不走success
其实ExtJs可以解析json格式的表单回执消息，格式为

{"success":true,....}

只要添加上这段就可以，根据success自动走success和failure代码了




完整代码：

Ext.require(['Ext.form.field.File', 'Ext.form.Panel', 'Ext.window.MessageBox']);

Ext.onReady(function() {

	Ext.create('Ext.form.Panel', {
		renderTo : Ext.getBody(),
		width : 500,
		frame : true,
		title : 'File Upload Form',
		bodyPadding : '10 10 0',

		defaults : {
			anchor : '100%',
			allowBlank : false,
			msgTarget : 'side',
			labelWidth : 30
		},

		items : [{
			xtype : 'filefield',
			id : 'form-file',
			emptyText : 'Select an file',
			fieldLabel : 'File',
			name : 'filePath',
			buttonText : '',
			buttonConfig : {
				iconCls : 'upload-icon'
			}
		}],
		buttons : [
				{
					text : 'Save',
					handler : function() {
						var form = this.up('form').getForm();
						if (form.isValid()) {
							form.submit({
								url : webRoot + 'rest/file/upload2',
								waitMsg : '正在上传文件...',
								success : function(form, action) {
									Ext.MessageBox.alert('成功','成功上传文件 "'	+ action.result.fileName+ '" 到服务器');
								},
								failure : function(form, action) {
									Ext.MessageBox.alert('失败','上传文件失败');
								}
							});
						}
					}
				}, {
					text : 'Reset',
					handler : function() {
						this.up('form').getForm().reset();
					}
				}]
	});

});

import java.io.File;
import java.io.IOException;
import java.io.Serializable;
import java.util.Iterator;
import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.codehaus.jackson.JsonGenerationException;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.ObjectMapper;
import org.springframework.stereotype.Component;

@Path(value = "file")
@Component
public class FileUpAndDownCtrl {

	class UploadRespnse implements Serializable {
		private String fileName;
		private Boolean success = false;;

		public String getFileName() {
			return fileName;
		}

		public void setFileName(String fileName) {
			this.fileName = fileName;
		}

		public Boolean getSuccess() {
			return success;
		}

		public void setSuccess(Boolean success) {
			this.success = success;
		}

	}

	@POST
	@Produces(MediaType.TEXT_HTML)
	/* 此处必须设置为TXT_HTML，否则ExtJS前台不能获得正确的返回 */
	@Path(value = "upload2")
	public String loadFile(@Context HttpServletRequest request) throws JsonGenerationException, JsonMappingException, IOException {

		UploadRespnse res = new UploadRespnse();
		String fileRepository = "c:/files/";
		if (ServletFileUpload.isMultipartContent(request)) {
			FileItemFactory factory = new DiskFileItemFactory();
			ServletFileUpload upload = new ServletFileUpload(factory);
			List<FileItem> items = null;
			try {
				items = upload.parseRequest(request);
			} catch (FileUploadException e) {
				e.printStackTrace();
			}
			if (items != null) {
				Iterator<FileItem> iter = items.iterator();
				while (iter.hasNext()) {
					FileItem item = iter.next();
					if (!item.isFormField() && item.getSize() > 0) {
						String fileName = processFileName(item.getName());
						try {
							item.write(new File(fileRepository + fileName));
							res.setSuccess(true);
							res.setFileName(fileName);
						} catch (Exception e) {
							e.printStackTrace();
							res.setSuccess(false);
						}
					}
				}
			}
		}
		ObjectMapper ob = new ObjectMapper();
		String resStr = ob.writeValueAsString(res);
		return resStr;
	}

	private String processFileName(String fileNameInput) {
		String fileNameOutput = null;
		fileNameOutput = fileNameInput.substring(fileNameInput.lastIndexOf("\\") + 1, fileNameInput.length());
		return fileNameOutput;
	}

}