Super streamlined json output class

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json, this stuff is hot, the earth to know. Online json analytic package is also very much, but most of the time, we just need to export json format on the server to the client, even I often do is value in the debug log output variables inside, so I wrote her a very streamlined json output format of the packet.

package com.kievnsoft.json;
import java.io.IOException;
import java.lang.reflect.Array;
import java.lang.reflect.Method;
import java.util.Calendar;
import java.util.Collection;
import java.util.Date;
import java.util.Map;

public class JsonObject {
    private static final char[] numbers = new char[]{'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'};
    private Calendar calendar = Calendar.getInstance();
    private StringBuilder sb = new StringBuilder();
    private boolean dateToText;
    private char[] ints = new char[16];
    public JsonObject(Object value) throws Exception {
        this(value, false);
    }
    public JsonObject(Object value, boolean dateToText) throws Exception {
        super();
        this.dateToText = dateToText;
        makeJson(value);
    }
    @Override
    public String toString() {
        return sb.toString();
    }
    public static String toJson(Object value) throws Exception {
        return toJson(value, false);
    }
    public static String toJson(Object value, boolean dateToText) throws Exception {
        JsonObject jo = new JsonObject(value);
        return jo.toString();
    }
    private void makeJson(Object value) throws Exception {
        if(value == null) {
            sb.append("null");
            return;
        }
       
        if(value instanceof String) {
            jsonString(value.toString());
        }
        else if(value instanceof Number) {
            sb.append(value.toString());
        }
        else if(value instanceof Date) {
            if(!dateToText)
                sb.append(((Date)value).getTime());
            else {
                sb.append('"');
                calendar.setTime((Date)value);
                formatInt(calendar.get(Calendar.YEAR), 4);
                sb.append(ints, 0, 4).append('-');
                formatInt(calendar.get(Calendar.MONTH), 2);
                sb.append(ints, 0, 2).append('-');
                formatInt(calendar.get(Calendar.DAY_OF_MONTH), 2);
                sb.append(ints, 0, 2).append(' ');
                formatInt(calendar.get(Calendar.HOUR_OF_DAY), 2);
                sb.append(ints, 0, 2).append(':');
                formatInt(calendar.get(Calendar.MINUTE), 2);
                sb.append(ints, 0, 2).append(':');
                formatInt(calendar.get(Calendar.SECOND), 2);
                sb.append(ints, 0, 2);
                sb.append('"');
            }
        }
        else if(value instanceof Collection) {
            sb.append('[');
            for(Object o : (Collection)value) {
                makeJson(o);
                sb.append(',');
            }
            sb.setCharAt(sb.length() - 1, ']');
        }
        else if(value instanceof Map) {
            sb.append('{');
            for(Map.Entry v : ((Map)value).entrySet()) {
                makeJson(v.getKey());
                sb.append(':');
                makeJson(v.getValue());
                sb.append(',');
            }
            sb.setCharAt(sb.length() - 1, '}');
        }
        else if(value.getClass().isArray()) {
            sb.append('[');
            int n = Array.getLength(value);
            for(int i = 0; i < n; ++i) {
                makeJson(Array.get(value, i));
                sb.append(',');
            }
            sb.setCharAt(sb.length() - 1, ']');
        }
        else if(value instanceof Boolean) {
            sb.append(value);
        }
        else if(value instanceof Character) {
            jsonString(String.valueOf(value));
        }
        else if(value instanceof Enum) {
            jsonString(((Enum)value).toString());
        }
        else {
            sb.append('{');
            Class cls = value.getClass();
            Method[] ms = cls.getMethods();
            for(Method v : ms) {
                String msn = v.getName();
                if(!msn.startsWith("get")
                        || msn.charAt(3) == '_'
                        || msn.equals("getClass")
                        || v.getParameterTypes().length > 0)
                    continue;
                sb.append(Character.toLowerCase(msn.charAt(3)));
                sb.append(msn, 4, msn.length()).append(':');
                makeJson(v.invoke(value));
                sb.append(',');
            }
            sb.setCharAt(sb.length() - 1, '}');
        }
    }
    private void jsonString(String str) throws IOException {
        char c;
        sb.append('"');
        for(int i = 0; i < str.length(); ++i) {
            c = str.charAt(i);
            switch (c) {
                case '"': sb.append("///""); break;
                case '/'':  sb.append("//'"); break;
                case '//': sb.append("////"); break;
                case '/': sb.append("///"); break;
                case '/b': sb.append("//b"); break;
                case '/f': sb.append("//f"); break;
                case '/n': sb.append("//n"); break;
                case '/r': sb.append("//r"); break;
                case '/t': sb.append("//t"); break;
                default: sb.append(c); break;
            }
        }
        sb.append('"');
    }
   
    private void formatInt(int value, int length) {
        for(int i = length - 1; i >= 0; --i) {
            if(value > 0) {
                ints[i] = numbers[value % 10];
                value = value / 10;
            }
            else ints[i] = '0';
        }
    }
}

 

Reproduced in: https: //my.oschina.net/kivensoft/blog/549367