<rt id="bn8ez"></rt>
<label id="bn8ez"></label>

  • <span id="bn8ez"></span>

    <label id="bn8ez"><meter id="bn8ez"></meter></label>

    隨筆-13  評論-28  文章-63  trackbacks-0
    http://json-lib.sourceforge.net/usage.html
    Using the JSONSerializer
    Working with arrays and collections
    Working with objects
    Working with XML

    Using the JSONSerializer

    JSONSerializer can transform any java object to JSON notation and back with a simple and clean interface, leveraging all the builders in JSONObject and JSONArray. To transform a java obect into JSON use JSONSerializer.toJSON(). To transform a valid JSON value (by JSON, I mean an Object implementing that interface), use toJava(). The last method is an instance method because the serializer needs special configuration to transform a JSON value to a bean class, array, List or DynaBean.

    Working with arrays and collections

    The simplest way to create a JSONArray from a java array or collection is through the static factory methods from JSONArray. JSONArray.fromObject() will inspect its parameter and call the correct factory or constructor.

    Examples:

    1. boolean[] boolArray = new boolean[]{true,false,true};  
    2. JSONArray jsonArray = JSONArray.fromObject( boolArray );  
    3. System.out.println( jsonArray );  
    4. // prints [true,false,true]  
    1. List list = new ArrayList();  
    2. list.add( "first" );  
    3. list.add( "second" );  
    4. JSONArray jsonArray = JSONArray.fromObject( list );  
    5. System.out.println( jsonArray );  
    6. // prints ["first","second"]  
    1. JSONArray jsonArray = JSONArray.fromObject( "['json','is','easy']" );  
    2. System.out.println( jsonArray );  
    3. // prints ["json","is","easy"]  

    Working with objects

    From Beans & Maps to JSON

    The simplest way to create a JSONObject from a bean or Map is through the static factory methods from JSONObject. JSONObject.fromObject() will inspect its parameter and call the correct factory or constructor.

    Examples:

    1. Map map = new HashMap();  
    2. map.put( "name""json" );  
    3. map.put( "bool", Boolean.TRUE );  
    4. map.put( "int"new Integer(1) );  
    5. map.put( "arr"new String[]{"a","b"} );  
    6. map.put( "func""function(i){ return this.arr[i]; }" );  
    7.   
    8. JSONObject json = JSONObject.fromObject( map );  
    9. System.out.println( jsonObject );  
    10. // prints ["name":"json","bool":true,"int":1,"arr":["a","b"],"func":function(i){ return this.arr[i]; }]  
    1. class MyBean{  
    2.    private String name = "json";  
    3.    private int pojoId = 1;  
    4.    private char[] options = new char[]{'a','f'};  
    5.    private String func1 = "function(i){ return this.options[i]; }";  
    6.    private JSONFunction func2 = new JSONFunction(new String[]{"i"},"return this.options[i];");  
    7.   
    8.    // getters & setters  
    9.    ...  
    10. }  
    11.   
    12. JSONObject jsonObject = JSONObject.fromObject( new MyBean() );  
    13. System.out.println( jsonObject );  
    14. /* prints 
    15.   {"name":"json","pojoId":1,"options":["a","f"], 
    16.   "func1":function(i){ return this.options[i];}, 
    17.   "func2":function(i){ return this.options[i];}} 
    18. */  
    CAUTION: when parsing, JSONObject and JSONArray will check for cycles in the hierarchy, throwing an exception if one is found. You can change this behavior by registering a CycleDetectionStrategy.

    From JSON to Beans

    Json-lib can transform JSONObjects to either a DynaBean or an specific bean class.
    When using DynaBean all arrays are converted to Lists, when using an specific bean class the transformation will use type conversion if necessary on array properties.

    Convert to DynaBean:

    1. String json = "{name=\"json\",bool:true,int:1,double:2.2,func:function(a){ return a; },array:[1,2]}";  
    2. JSONObject jsonObject = JSONObject.fromObject( json );  
    3. Object bean = JSONObject.toBean( jsonObject );  
    4. assertEquals( jsonObject.get( "name" ), PropertyUtils.getProperty( bean, "name" ) );  
    5. assertEquals( jsonObject.get( "bool" ), PropertyUtils.getProperty( bean, "bool" ) );  
    6. assertEquals( jsonObject.get( "int" ), PropertyUtils.getProperty( bean, "int" ) );  
    7. assertEquals( jsonObject.get( "double" ), PropertyUtils.getProperty( bean, "double" ) );  
    8. assertEquals( jsonObject.get( "func" ), PropertyUtils.getProperty( bean, "func" ) );  
    9. List expected = JSONArray.toList( jsonObject.getJSONArray( "array" ) );  
    10. Assertions.assertListEquals( expected, (List) PropertyUtils.getProperty( bean, "array" ) );  

    Convert to Bean:

    1. String json = "{bool:true,integer:1,string:\"json\"}";  
    2. JSONObject jsonObject = JSONObject.fromObject( json );  
    3. BeanA bean = (BeanA) JSONObject.toBean( jsonObject, BeanA.class );  
    4. assertEquals( jsonObject.get( "bool" ), Boolean.valueOf( bean.isBool() ) );  
    5. assertEquals( jsonObject.get( "integer" ), new Integer( bean.getInteger() ) );  
    6. assertEquals( jsonObject.get( "string" ), bean.getString() );  

    There are two special cases when converting to an specific bean, if the target bean has a Map property and it must contain other beans, JSONObject.toBean() will transform the nested beans into DynaBeans. If you need those nested beans transformed into an specific class, you can either postprocess the Map attribute or provide hints on JSONObject's attributes for conversion. JSONObject.toBean() may be passed a third argument, a Map, that will provide thos hints. Every key must be either the name of a property or a regular expression matching the object's properties, and the value must be a Class.

    The second case is similar and it happens when the target bean has a Collection (List) as a property and it must contain other beans. In this case there is no way to provide hints for class conversion. The only possible solution is to postprocess the collection transforming each DynaBean into an specific bean.

    To ease the postprocessing scenarios, EZMorph provides a Morpher capable of transforming a DynaBean into an specific bean, BeanMorpher
    Example:

    1. class MyBean{  
    2.    private List data;  
    3.    // getters & setters  
    4. }  
    5.   
    6. class Person{  
    7.    private String name;  
    8.    // getters & setters  
    9. }  
    10.   
    11. ...  
    12.   
    13. String json = "{'data':[{'name':'Wallace'},{'name':'Grommit'}]}";  
    14. Map classMap = new HashMap();  
    15. classMap.put( "data", Person.class );  
    16. MyBean bean = JSONObject.toBean( json, MyBean.class, classMap );  

    This yields a MyBean instance that has DynaBeans inside the 'data' attribute', so now comes the part of postprocessing, this can be done with an Iterator
    Example:

    1. Morpher dynaMorpher = new BeanMorpher( Person.class, JSONUtils.getMorpherRegistry() );  
    2. morpherRegistry.registerMorpher( dynaMorpher );  
    3. List output = new ArrayList();  
    4. for( Iterator i = bean.getData().iterator(); i.hasNext(); ){  
    5.    output.add( morpherRegistry.morph( Person.class, i.next() ) );  
    6. }  
    7. bean.setData( output );  

    To learn more about Morphers, please visit .

    Working with XML

    Working with XML has become easier since version 1.1. Transforming JSONObjects and JSONArrays from and to XML is done through the XMLSerializer.

    From JSON to XML

    Writing to JSON to XML is as simple as calling XMLSerializer.write(), but there are a lot of options that you may configure to get better control of the XML output. For example you may change the default names for the root element ('o' if object, 'a' if array), the default name for object (an object inside an array is "anonymous"), the default name for array (for the same reason as object), the default name for element (array items have no name). If you'd like to output namescape information but your JSON does not includes it, no problem, you have 8 methods that will let you register and manage namespaces; namespaces defined this way have precedence on any namespace declaration that may be inside the JSON. By default XMLSerializer will append special attributes to each xml element for easing the transformation back to JSON but you may configure it to skip appending those attributes. Any property on a JSONObject that begins with '@' will be treated as an attribute, any property named '#text' will be treated as a Text node.

    Please review the javadoc for XMLSerializer to know more about the configurable options.

    Code XML output
    1. JSONObject json = new JSONObject( true );  
    2. String xml = XMLSerializer.write( json );  
    1. <o class="object" null="true">  
    2.       
    1. JSONObject json = JSONObject.fromObject("{\"name\":\"json\",\"bool\":true,\"int\":1}");  
    2. String xml = XMLSerializer.write( json );  
    1. <o class="object">  
    2.    <name type="string">json</name>  
    3.    <bool type="boolean">true</bool>  
    4.    <int type="number">1</int>  
    5. </o>  
    1. JSONArray json = JSONArray.fromObject("[1,2,3]");  
    2. String xml = XMLSerializer.write( json );  
    1. <a class="array"<  
    2.    <e type="number">1</e>  
    3.    <e type="number">2</e>  
    4.    <e type="number">3</e>  
    5. </a>  

    From XML to JSON

    XMLSerializer treats each element as a string unless a type parameter is specified.
    JSONFunction needs an additional parameter that specifies that function's params.
    All xml attributes will have the prefix '@' and text nodes will have the property name '#text'. XMLSerializer supports the rules outlined at Converting Between XML and JSON

    XML input Code
    1. <a class="array">  
    2.   <e type="function" params="i,j">  
    3.       return matrix[i][j];  
    4.   </e>  
    5. </a>  
    1. JSONArray json = (JSONArray) XMLSerializer.read( xml );  
    2. System.out.println( json );  
    3. // prints [function(i,j){ return matrix[i][j]; }]  
    CAUTION: when parsing, JSONObject and JSONArray will check for cycles in the hierarchy, throwing an exception if one is found. You can change this behavior by registering a CycleDetectionStrategy.

    © 2006-2007 Json-lib

    posted on 2007-09-05 13:36 七匹狼 閱讀(4902) 評論(1)  編輯  收藏 所屬分類: json

    評論:
    # re: json in java 介紹 2007-10-11 15:24 | 有貓相伴的日子

    只有注冊用戶登錄后才能發(fā)表評論。


    網(wǎng)站導(dǎo)航:
     
    主站蜘蛛池模板: 97人妻精品全国免费视频 | 亚洲日韩国产成网在线观看| 久久久久久毛片免费播放| 国产免费131美女视频| 日韩免费观看一区| 一级**爱片免费视频| 国产亚洲一区二区三区在线| 国产成人青青热久免费精品| 日韩免费a级毛片无码a∨ | 国产hs免费高清在线观看| 91精品免费在线观看| 久久免费观看国产99精品| 国产免费内射又粗又爽密桃视频| 亚洲AV成人无码久久WWW| 亚洲人成影院在线观看| 国产精品极品美女免费观看| 午夜免费1000部| 曰批视频免费40分钟试看天天| 东方aⅴ免费观看久久av| 国产黄片不卡免费| 国产亚洲成av人片在线观看| 亚洲欧洲日本在线| 亚洲?v无码国产在丝袜线观看| 日韩中文无码有码免费视频 | 国产免费卡一卡三卡乱码| 美女网站免费福利视频| **真实毛片免费观看| 1000部禁片黄的免费看| 69视频在线是免费观看| 97青青草原国产免费观看| 日本免费大黄在线观看| 在线免费中文字幕| 91精品成人免费国产片| 国产大片免费网站不卡美女| ww在线观视频免费观看| 青青草免费在线视频| 国产男女猛烈无遮挡免费视频网站| 国产免费区在线观看十分钟| 特级做A爰片毛片免费看无码| 国产色爽免费无码视频| 91在线手机精品免费观看|