/**
 * Alipay.com Inc.
 * Copyright (c) 2004-2012 All Rights Reserved.
 */
package com.alipay.zdal.parser.sql.util;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.StringWriter;
import java.text.SimpleDateFormat;

/**
 * 
 * @author ����
 * @version $Id: IOUtils.java, v 0.1 2012-11-17 ����3:55:38 Exp $
 */
public class IOUtils {

    public final static int DEFAULT_BUFFER_SIZE = 1024 * 4;

    public static String read(InputStream in) {
        InputStreamReader reader = new InputStreamReader(in);
        return read(reader);
    }

    public static String readFromResource(String resource) throws IOException {
        InputStream in = null;
        try {
            in = Thread.currentThread().getContextClassLoader().getResourceAsStream(resource);
            if (in == null) {
                return null;
            }

            String text = IOUtils.read(in);
            return text;
        } finally {
            JdbcUtils.close(in);
        }
    }

    public static String read(Reader reader) {
        try {

            StringWriter writer = new StringWriter();

            char[] buffer = new char[DEFAULT_BUFFER_SIZE];
            int n = 0;
            while (-1 != (n = reader.read(buffer))) {
                writer.write(buffer, 0, n);
            }

            return writer.toString();
        } catch (IOException ex) {
            throw new IllegalStateException("read error", ex);
        }
    }

    public static String read(Reader reader, int length) {
        try {
            char[] buffer = new char[length];

            int offset = 0;
            int rest = length;
            int len;
            while ((len = reader.read(buffer, offset, rest)) != -1) {
                rest -= len;
                offset += len;

                if (rest == 0) {
                    break;
                }
            }

            return new String(buffer, 0, length - rest);
        } catch (IOException ex) {
            throw new IllegalStateException("read error", ex);
        }
    }

    public static String toString(java.util.Date date) {
        if (date == null) {
            return null;
        }
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        return format.format(date);
    }

    public static String getStackTrace(Throwable ex) {
        StringWriter buf = new StringWriter();
        ex.printStackTrace(new PrintWriter(buf));

        return buf.toString();
    }

    public static String toString(StackTraceElement[] stackTrace) {
        StringBuilder buf = new StringBuilder();
        for (StackTraceElement item : stackTrace) {
            buf.append(item.toString());
            buf.append("\n");
        }
        return buf.toString();
    }

}