Convert 组件介绍

       Convert 是一个比较独立的组件，仅依赖于util包。提供Java对象的序列化与反解析功能。支持JSON(JavaScript Object Notation)、BSON(Binary Stream Object Notation)两种格式化。 两种格式使用方式完全一样，其性能都大幅度超过其他JSON框架。

Convert 快速上手

      本介绍仅以JSON为例(BSON与JSON使用方式雷同)。其操作类主要是JsonConvert，配置类主要是JsonFactory、ConvertColumn。

      JsonConvert 序列化方法：

    public String convertTo(Object value);

    public String convertTo(final Type type, Object value);

    public void convertTo(final JsonWriter out, Object value);

    public void convertTo(final JsonWriter out, final Type type, Object value);

    public ByteBuffer[] convertTo(final Supplier<ByteBuffer> supplier, final Type type, Object value);

    public ByteBuffer[] convertTo(final Charset charset, final Supplier<ByteBuffer> supplier, final Type type, Object value);

    public ByteBuffer[] convertTo(final Supplier<ByteBuffer> supplier, Object value);

    public ByteBuffer[] convertTo(final Charset charset, final Supplier<ByteBuffer> supplier, Object value);

      JsonConvert 反解析方法：

    public <T> T convertFrom(final Type type, final String text);

    public <T> T convertFrom(final Type type, final char[] text);

    public <T> T convertFrom(final Type type, final char[] text, int start, int len);

    public <T> T convertFrom(final Type type, final ByteBuffer... buffers);

      范例：

    public class UserRecord {

        private int userid;

        private String username = "";

        private String password = "";

        public UserRecord() {
        }

        /** 以下省略getter setter方法 */
    }

    public static void main(String[] args) throws Exception {
        UserRecord user = new UserRecord();
        user.setUserid(100);
        user.setUsername("redkalename");
        user.setPassword("123456");
        final JsonConvert convert = JsonFactory.root().getConvert();
        String json = convert.convertTo(user);
        System.out.println(json);  //应该是 {"password":"123456","userid":100,"username":"redkalename"}
        UserRecord user2 = convert.convertFrom(UserRecord.class, json);
        System.out.println(convert.convertTo(user2)); //应该也是 {"password":"123456","userid":100,"username":"redkalename"}
        
        /**
         * 以下功能是为了屏蔽password字段。
         * 等价于 public String getPassword() 加上 @ConvertColumn ：
         *
         *      @ConvertColumn(ignore = true, type = ConvertType.JSON)
         *      public String getPassword() {
         *          return password;
         *      }
         **/
        final JsonFactory childFactory = JsonFactory.root().createChild();
        childFactory.register(UserRecord.class, true, "password");
        childFactory.reloadCoder(UserRecord.class);
        final JsonConvert childConvert = childFactory.getConvert();
        json = childConvert.convertTo(user);
        System.out.println(json);  //应该是 {"userid":100,"username":"redkalename"}
        user2 = childConvert.convertFrom(UserRecord.class, json);
        System.out.println(childConvert.convertTo(user2)); //应该也是 {"userid":100,"username":"redkalename"}
    }

      JsonConvert 支持非空构造函数：

public class UserRecord {

    private int userid;

    private String username = "";

    private String password = "";

    @java.beans.ConstructorProperties({"userid", "username", "password"})
    public UserRecord(int userid, String username, String password) {
        this.userid = userid;
        this.username = username;
        this.password = password;
    }

    public int getUserid() {
        return userid;
    }

    public String getUsername() {
        return username;
    }

    public String getPassword() {
        return password;
    }
}