/* * To change this template, choose Tools | Templates * and open the template in the editor. */package com.hadeslee.audiotag.tag.ape;import com.hadeslee.yoyoplayer.util.Util;import java.util.Arrays;import java.util.logging.Level;import java.util.logging.Logger;/** * 內部的私有類,它代表了一個APE標簽的頭部 * @author hadeslee */public class TagHead {    private static Logger log = Logger.getLogger(TagHead.class.getName());    private byte[] data;//頭部的數據    private boolean valid;//是否是合法的頭部    private int version = 2000;//版本,默認是2000    private int tagSize;//標簽的長度,包括尾標簽以及所有的項目,不包括頭標簽    private int itemCount;//項目的數量    private int flag = FOOT;//標簽的其它標志,指示它是頭部還是尾部    public static final int HEAD = 0xA0000000;    public static final int FOOT = 0x80000000;    public static final int V1=1000;//表示APE的版本號    public static final int V2=2000;    private int index;//這個標頭的起始點的位置,相對于文件    public TagHead(byte[] data) {        this.data = data;        parseData();    }    public TagHead() {    }    public int getIndex() {        return index;    }    public void setIndex(int index) {        this.index = index;    }    public byte[] getBytes() {        //標頭總共是32個字節        byte[] head = new byte[32];        byte[] temp = {(byte) 'A',            (byte) 'P',            (byte) 'E',            (byte) 'T',            (byte) 'A',            (byte) 'G',            (byte) 'E',            (byte) 'X'        };        //先把頭的標量填進去,8字節        System.arraycopy(temp, 0, head, 0, 8);        temp = Util.getBytesFromInt(version);        //再把版本號寫進去,4字節        System.arraycopy(temp, 0, head, 8, 4);        temp = Util.getBytesFromInt(tagSize);        log.log(Level.SEVERE,"TAGSIZE="+tagSize);        //再把標簽的長度寫進去,4字節        System.arraycopy(temp, 0, head, 12, 4);        temp = Util.getBytesFromInt(itemCount);        //再把標簽的數量寫進去,4字節        System.arraycopy(temp, 0, head, 16, 4);        temp = Util.getBytesFromInt(flag);        //再把標志寫進去,表示是標簽頭部還是尾部        System.arraycopy(temp, 0, head, 20, 4);        //把標志空的8個字節進去,因為默認就是空的,所以不用寫了        //頭部或者尾部的數據塊已經構造好了        return head;    }    private void parseData() {        try {            checkHead();            checkVersion();            checkTagSize();            checkItemCount();            checkFlag();            valid = true;        } catch (Exception exe) {            log.log(Level.SEVERE, "分析標簽異常!");            valid = false;        }    }    /**     * 這個標簽是否有頭標簽,因為一般讀都是從尾部讀過去的     * @return 是否有頭標簽,重寫的時候有用     */    public boolean hasHeader() {        return ((1 << 31) & flag) != 0;    }    /**     * 檢查頭部八個字節的的數據是否一樣     */    private void checkHead() {        byte[] temp = new byte[8];        byte[] head = {(byte) 'A',            (byte) 'P',            (byte) 'E',            (byte) 'T',            (byte) 'A',            (byte) 'G',            (byte) 'E',            (byte) 'X'        };        System.arraycopy(data, 0, temp, 0, 8);        //比較兩個頭部的數據是否一樣,這是第一要素        if (!Arrays.equals(head, temp)) {            throw new RuntimeException("頭部數據不一樣!");        }    }    /**     * 檢查版本號是否合法,必須是1000或者2000     */    private void checkVersion() {        byte[] temp = new byte[4];        System.arraycopy(data, 8, temp, 0, 4);        int v = Util.getInt(temp);        if (v == 2000 || v == 1000) {            version = v;            log.log(Level.INFO, "版本號是:" + v);        } else {            throw new RuntimeException("版本號不合法!!");        }    }    private void checkTagSize() {        byte[] temp = new byte[4];        System.arraycopy(data, 12, temp, 0, 4);        tagSize = Util.getInt(temp);        log.log(Level.INFO, "標簽大小:" + tagSize);    }    private void checkItemCount() {        byte[] temp = new byte[4];        System.arraycopy(data, 16, temp, 0, 4);        itemCount = Util.getInt(temp);        log.log(Level.INFO, "標簽項目數:" + itemCount);    }    private void checkFlag() {        byte[] temp = new byte[4];        System.arraycopy(data, 20, temp, 0, 4);        flag = Util.getInt(temp);        log.log(Level.INFO, "標志:" + flag);    }    public void setFlag(int flag) {        this.flag = flag;    }    public void setItemCount(int itemCount) {        this.itemCount = itemCount;    }    public void setTagSize(int tagSize) {        this.tagSize = tagSize;    }    public void setVersion(int version) {        if(!(version==V1||version==V2)){            throw new RuntimeException("非法的版本號,只能是V2或者V1.");        }        this.version = version;    }    public int getFlag() {        return flag;    }    public int getItemCount() {        return itemCount;    }    public int getTagSize() {        return tagSize;    }    public boolean isValid() {        return valid;    }    public int getVersion() {        return version;    }    public static void main(String[] args) {    }    }