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/*
 * Copyright 1999-2018 Alibaba Group Holding Ltd.
 *
 * 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.alibaba.druid.support.json;

import java.text.SimpleDateFormat;
import java.util.Collection;
import java.util.Date;
import java.util.Map;

import javax.management.openmbean.CompositeData;
import javax.management.openmbean.TabularData;

import com.alibaba.druid.sql.visitor.SQLEvalVisitor;
import com.alibaba.druid.util.Utils;

public class JSONWriter {

    private StringBuilder    out;



    public JSONWriter(){
        this.out = new StringBuilder();
    }

    public void writeArrayStart() {
        write('[');
    }

    public void writeComma() {
        write(',');
    }

    public void writeArrayEnd() {
        write(']');
    }
    
    public void writeNull() {
        write("null");
    }
    
    @SuppressWarnings({ "unchecked", "rawtypes" })
    public void writeObject(Object o) {
        if (o == null) {
            writeNull();
            return;
        }

        if (o instanceof String) {
            writeString((String) o);
            return;
        }

        if (o instanceof Number) {
            write(o.toString());
            return;
        }

        if (o instanceof Boolean) {
            write(o.toString());
            return;
        }

        if (o instanceof Date) {
            writeDate((Date) o);
            return;
        }

        if (o instanceof Collection) {
            writeArray((Collection) o);
            return;
        }

        if (o instanceof Throwable) {
            writeError((Throwable) o);
            return;
        }

        if (o instanceof int[]) {
            int[] array = (int[]) o;
            write('[');
            for (int i = 0; i < array.length; ++i) {
                if (i != 0) {
                    write(',');
                }
                write(array[i]);
            }
            write(']');
            return;
        }

        if (o instanceof long[]) {
            long[] array = (long[]) o;
            write('[');
            for (int i = 0; i < array.length; ++i) {
                if (i != 0) {
                    write(',');
                }
                write(array[i]);
            }
            write(']');
            return;
        }

        if (o instanceof TabularData) {
            writeTabularData((TabularData) o);
            return;
        }

        if (o instanceof CompositeData) {
            writeCompositeData((CompositeData) o);
            return;
        }

        if (o instanceof Map) {
            writeMap((Map) o);
            return;
        }
        
        if (o == SQLEvalVisitor.EVAL_VALUE_NULL) {
            write("null");
            return;
        }

        throw new IllegalArgumentException("not support type : " + o.getClass());
    }

    public void writeDate(Date date) {
        if (date == null) {
            writeNull();
            return;
        }
        //SimpleDataFormat is not thread-safe, we need to make it local.
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        writeString(dateFormat.format(date));
    }

    public void writeError(Throwable error) {
        if (error == null) {
            writeNull();
            return;
        }

        write("{\"Class\":");
        writeString(error.getClass().getName());
        write(",\"Message\":");
        writeString(error.getMessage());
        write(",\"StackTrace\":");
        writeString(Utils.getStackTrace(error));
        write('}');
    }

    public void writeArray(Object[] array) {
        if (array == null) {
            writeNull();
            return;
        }

        write('[');

        for (int i = 0; i < array.length; ++i) {
            if (i != 0) {
                write(',');
            }
            writeObject(array[i]);
        }

        write(']');
    }

    public void writeArray(Collection