JavaBean与JSON的转换

<p><span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">阿里巴巴开源的FastJSON，效率是非常高的。一般用来转大量的JSON数据。</span></p>

下面介绍一些应用：

将JSON数据转换成JavaBean

JSON:

<pre name="code" class="plain">{ "EncodeCapability" : { "ChannelMaxSetSync" : 0, "CombEncodeInfo" : [ { "CompressionMask" : "0x00000000", "Enable" : true, "HaveAudio" : true, "ResolutionMask" : "0x00000000", "StreamType" : "MainStream" }, { "CompressionMask" : "0x00000000", "Enable" : false, "HaveAudio" : false, "ResolutionMask" : "0x00000000", "StreamType" : "ExtraStream2" }, { "CompressionMask" : "0x00000000", "Enable" : false, "HaveAudio" : false, "ResolutionMask" : "0x00000000", "StreamType" : "ExtraStream3" }, { "CompressionMask" : "0x00000000", "Enable" : false, "HaveAudio" : false, "ResolutionMask" : "0x00000000", "StreamType" : "ExtraStream4" }, { "CompressionMask" : "0x00000000", "Enable" : false, "HaveAudio" : false, "ResolutionMask" : "0x00000000", "StreamType" : "JPEGStream" } ], "Compression" : "0x00000000", "EncodeInfo" : [ { "CompressionMask" : "0x00000080", "Enable" : true, "HaveAudio" : true, "ResolutionMask" : "0xF5FFFFFF", "StreamType" : "MainStream" }, { "CompressionMask" : "0x00000080", "Enable" : true, "HaveAudio" : true, "ResolutionMask" : "0xF5F7FFFF", "StreamType" : "ExtraStream2" }, { "CompressionMask" : "0x00000000", "Enable" : false, "HaveAudio" : false, "ResolutionMask" : "0x00000000", "StreamType" : "ExtraStream3" }, { "CompressionMask" : "0x00000000", "Enable" : false, "HaveAudio" : false, "ResolutionMask" : "0x00000000", "StreamType" : "ExtraStream4" }, { "CompressionMask" : "0x00000080", "Enable" : true, "HaveAudio" : true, "ResolutionMask" : "0xF5F7FFFF", "StreamType" : "JPEGStream" } ], "ExImageSizePerChannel" : [ "0x00000009" ], "ExImageSizePerChannelEx" : [ [ "0x00000018", "0x55402CD8", "0x402E5988", "0x00000018", "0x00000010", "0x00000078", "0x00000040", "0x55402D50", "0x402E7D78", "0x00000010", "0x00000057", "0x00000009", "0x00000009", "0x00000011", "0x00000009", "0x400834B9", "0xFFFFFFFF", "0x00000000", "0x00000073", "0x00000000", "0x00000020", "0x00000000", "0x00000001", "0x00000013", "0x00010000", "0x00000000", "0x00000000", "0x00000000", "0x00000000", "0x00000000", "0x00000000", "0x00000000" ] ], "ImageSizePerChannel" : [ "0x00000801" ], "MaxBitrate" : 49152, "MaxEncodePower" : 38016000, "MaxEncodePowerPerChannel" : [ "0x02441400" ] }, "Name" : "EncodeCapability", "Ret" : 100, "SessionID" : "0x00000289" }

JavaBean:

package com.mobile.bean;import java.util.ArrayList;import java.util.List;import com.alibaba.fastjson.annotation.JSONField;public class EncodeCapabilityJSON {@JSONField(name="ChannelMaxSetSync")public Integer channelMaxSetSync;@JSONField(name="CombEncodeInfo")public List<CombAndEncodeInfo> combEncodeInfo = new ArrayList<CombAndEncodeInfo>();@JSONField(name="Compression")public String compression;@JSONField(name="EncodeInfo")public List<CombAndEncodeInfo> encodeInfo = new ArrayList<CombAndEncodeInfo>();@JSONField(name="ExImageSizePerChannel")public List<String> exImageSizePerChannel;@JSONField(name="ExImageSizePerChannelEx")public String exImageSizePerChannelEx[][];@JSONField(name="ImageSizePerChannel")public List<String> imageSizePerChannel;@JSONField(name="MaxEncodePowerPerChannel")public List<String> maxEncodePowerPerChannel;@JSONField(name="MaxBitrate")public Integer maxBitrate;@JSONField(name="MaxEncodePower")public Integer maxEncodePower;public Integer getChannelMaxSetSync() {return channelMaxSetSync;}public void setChannelMaxSetSync(Integer channelMaxSetSync) {this.channelMaxSetSync = channelMaxSetSync;}public List<CombAndEncodeInfo> getCombEncodeInfo() {return combEncodeInfo;}public void setCombEncodeInfo(List<CombAndEncodeInfo> combEncodeInfo) {this.combEncodeInfo = combEncodeInfo;}public String getCompression() {return compression;}public void setCompression(String compression) {this.compression = compression;}public List<CombAndEncodeInfo> getEncodeInfo() {return encodeInfo;}public void setEncodeInfo(List<CombAndEncodeInfo> encodeInfo) {this.encodeInfo = encodeInfo;}public List<String> getExImageSizePerChannel() {return exImageSizePerChannel;}public void setExImageSizePerChannel(List<String> exImageSizePerChannel) {this.exImageSizePerChannel = exImageSizePerChannel;}public String[][] getExImageSizePerChannelEx() {return exImageSizePerChannelEx;}public void setExImageSizePerChannelEx(String[][] exImageSizePerChannelEx) {this.exImageSizePerChannelEx = exImageSizePerChannelEx;}public List<String> getImageSizePerChannel() {return imageSizePerChannel;}public void setImageSizePerChannel(List<String> imageSizePerChannel) {this.imageSizePerChannel = imageSizePerChannel;}public List<String> getMaxEncodePowerPerChannel() {return maxEncodePowerPerChannel;}public void setMaxEncodePowerPerChannel(List<String> maxEncodePowerPerChannel) {this.maxEncodePowerPerChannel = maxEncodePowerPerChannel;}public Integer getMaxBitrate() {return maxBitrate;}public void setMaxBitrate(Integer maxBitrate) {this.maxBitrate = maxBitrate;}public Integer getMaxEncodePower() {return maxEncodePower;}public void setMaxEncodePower(Integer maxEncodePower) {this.maxEncodePower = maxEncodePower;}}

转换的方法：

<pre name="code" class="java">/*** @Title: json2String * @Description: TODO * @param @param json* @param @return     * @return String    * @throws * @add 提前JSON中包含的JSON，对包含的JSON处理，转换成JavaBean */public static String json2String(String json) {JSONObject jo = JSON.parseObject(json);Set<String> key = jo.keySet();Iterator iterator = key.iterator();String keyName = null;String keyClassName = null;while (iterator.hasNext()) {keyName = (String) iterator.next();keyClassName = jo.get(keyName).getClass().getName();if (("com.alibaba.fastjson.JSONObject").equals(keyClassName)) {return jo.getString(keyName);}}return null;}/** * * @Title: jsonstr2JavaBean * @Description: 将json和bean对象进行转换 */public static Object jsonstr2JavaBean(String json, Object object) {object = JSON.parseObject(json, object.getClass());return object;}

....

<pre name="code" class="java"><pre name="code" class="java">EncodeCapabilityJSON bcj = new EncodeCapabilityJSON();bcj = (EncodeCapabilityJSON)jsonstr2JavaBean(json2String(jsonString),bcj);

总结下，主要使用到的方法是：JSON.parseObject(String text,Class<? extendsObject> clazz),可以将JSON直接转换成Bean。

需要注意的是，我们接到的JSON数据，往往也要传出去，传出去的时候，首字母可能会大写，这个时候使用注解帮忙，

@JSONField(name="ChannelMaxSetSync")public Integer channelMaxSetSync;

它会将数据一一对应传输出去。

当然还有一些其他方法可能会被用到。

import com.alibaba.fastjson.JSON;public static final Object parse(String text); // 把JSON文本parse为JSONObject或者JSONArraypublic static final JSONObject parseObject(String text)； // 把JSON文本parse成JSONObjectpublic static final <T> T parseObject(String text, Class<T> clazz); // 把JSON文本parse为JavaBeanpublic static final JSONArray parseArray(String text); // 把JSON文本parse成JSONArraypublic static final <T> List<T> parseArray(String text, Class<T> clazz); //把JSON文本parse成JavaBean集合public static final String toJSONString(Object object); // 将JavaBean序列化为JSON文本public static final String toJSONString(Object object, boolean prettyFormat); // 将JavaBean序列化为带格式的JSON文本public static final Object toJSON(Object javaObject);// 将JavaBean转换为JSONObject或者JSONArray。

值得注意的是，FastJson单次只能解析一个JSON数据，如果JSON中包含其他JSON的话，其他JSON是不能被解析的。（我还没找到好的方法）