/**
* Copyright (c) 2011-2012, James Zhan 詹波 (jfinal@126.com).
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.jfinal.ext.render;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import com.jfinal.kit.JsonKit;
import com.jfinal.render.Render;
import com.jfinal.render.RenderException;
/**
* JsonRenderWithContentType
*/
public class JsonWithContentTypeRender extends Render {
private static final long serialVersionUID = 3672646716279300085L;
private String key;
private Object value;
private String[] attrs;
private String contentType;
public JsonWithContentTypeRender(String contentType) {
this.contentType = contentType;
}
public JsonWithContentTypeRender(String key, Object value, String contentType) {
this.key = key;
this.value = value;
this.contentType = contentType;
}
public JsonWithContentTypeRender(String[] attrs, String contentType) {
this.attrs = attrs;
this.contentType = contentType;
}
public void render() {
String jsonText = buildJsonText();
PrintWriter writer = null;
try {
response.setHeader("Pragma", "no-cache"); // HTTP/1.0 caches might not implement Cache-Control and might only implement Pragma: no-cache
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
response.setContentType(contentType + ";charset=" + getEncoding());
writer = response.getWriter();
writer.write(jsonText);
writer.flush();
} catch (IOException e) {
throw new RenderException(e);
}
finally {
if (writer != null)
writer.close();
}
}
private static final int depth = 8;
@SuppressWarnings({"rawtypes", "unchecked"})
private String buildJsonText() {
Map map = new HashMap();
if (key != null) {
map.put(key, value);
}
else if (attrs != null) {
for (String key : attrs)
map.put(key, request.getAttribute(key));
}
else {
Enumeration<String> attrs = request.getAttributeNames();
while (attrs.hasMoreElements()) {
String key = attrs.nextElement();
Object value = request.getAttribute(key);
map.put(key, value);
}
}
return JsonKit.mapToJson(map, depth);
}
}