Java 正在获取数组索引越界异常和Can';我找不到源头

Java 正在获取数组索引越界异常和Can';我找不到源头,java,arrays,Java,Arrays,这个程序编译得很好。这是HeadFirstJava的一个教程程序,我很确定我输入的是正确的,但我得到的索引是越界错误。我知道这个错误意味着什么,但就我的一生而言,我看不出我错在哪里 import java.awt.*; import javax.swing.*; import javax.sound.midi.*; import java.util.*; import java.awt.event.*; public class BeatBox{ JPanel mainPanel;

这个程序编译得很好。这是HeadFirstJava的一个教程程序,我很确定我输入的是正确的,但我得到的索引是越界错误。我知道这个错误意味着什么,但就我的一生而言,我看不出我错在哪里

import java.awt.*;
import javax.swing.*;
import javax.sound.midi.*;
import java.util.*;
import java.awt.event.*;

public class BeatBox{

    JPanel mainPanel;
    ArrayList<JCheckBox> checkBoxList;
    Sequencer sequencer;
    Sequence sequence; 
    Track track;
    JFrame theFrame;

    String[] instrumentNames = {"Bass Drum", "Closed High-Hat",
    "Open Hi-Hat", "Acoustic Snare", "Crash Cymbal", "Hand Clap",
    "High Tom", "High Bongo", "Maracas", "Whistle", "Low Conga",
    "Open High Conga"};
    int[] instruments = {35,42,46,38,49,39,50,60,70,72,64,56,58,47,67,63};

    public static void main(String[] args){
        BeatBox box = new BeatBox();
        box.buildGUI();
    }

    public void buildGUI(){
        theFrame = new JFrame("Cyber BeatBox");
        theFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        BorderLayout layout = new BorderLayout();
        JPanel background = new JPanel(layout);
        background.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));

        checkBoxList = new ArrayList<JCheckBox>();
        Box buttonBox = new Box(BoxLayout.Y_AXIS);

        JButton start = new JButton("Start");
        start.addActionListener(new MyStartListener());
        buttonBox.add(start);

        JButton stop = new JButton("Stop");
        stop.addActionListener(new MyStopListener());
        buttonBox.add(stop);

        JButton upTempo = new JButton("Tempo Up");
        upTempo.addActionListener(new MyUpTempoListener());
        buttonBox.add(upTempo);

        JButton downTempo = new JButton("Tempo Down");
        downTempo.addActionListener(new MyDownTempoListener());
        buttonBox.add(downTempo);

        Box nameBox = new Box(BoxLayout.Y_AXIS);
        for(int i = 0; i < 16; i++){
            nameBox.add(new Label(instrumentNames[i]));
        }

        background.add(BorderLayout.EAST, buttonBox);
        background.add(BorderLayout.WEST, nameBox);

        theFrame.getContentPane().add(background);

        GridLayout grid = new GridLayout(20,20);
        grid.setVgap(1);
        grid.setHgap(2);
        mainPanel = new JPanel(grid);
        background.add(BorderLayout.CENTER, mainPanel);

        for(int i = 0; i < 256; i++){
            JCheckBox c = new JCheckBox();
            c.setSelected(false);
            checkBoxList.add(c);
            mainPanel.add(c);
        }

        setUpMidi();

        theFrame.setBounds(50,50,300,300);
        theFrame.pack();
        theFrame.setVisible(true);
    }

    public void setUpMidi(){
        try{
            sequencer = MidiSystem.getSequencer();
            sequencer.open();
            sequence = new Sequence(Sequence.PPQ, 4);
            track = sequence.createTrack();
            sequencer.setTempoInBPM(120);
        }catch(Exception e){e.printStackTrace();}
    }

    public void buildTrackAndStart(){
        int[] trackList = null;

        sequence.deleteTrack(track);
        track = sequence.createTrack();

        for(int i = 0; i < 16; i++){
            trackList = new int[16];

            int key = instruments[i];

            for(int j = 0; j < 16; j++){

                JCheckBox jc = (JCheckBox)checkBoxList.get(j + (16 * i));
                if(jc.isSelected()){
                    trackList[j] = key;
                }else{
                    trackList[j] = 0;
                }
            }

            makeTracks(trackList);
            track.add(makeEvent(176,1,127,0,16));
        }

        track.add(makeEvent(192,9,1,0,15));
        try{
            sequencer.setSequence(sequence);
            sequencer.setLoopCount(sequencer.LOOP_CONTINUOUSLY);
            sequencer.start();
            sequencer.setTempoInBPM(120);
        }catch(Exception e){e.printStackTrace();}
    }

    public class MyStartListener implements ActionListener{
        public void actionPerformed(ActionEvent a){
            buildTrackAndStart();
        }
    }

    public class MyStopListener implements ActionListener{
        public void actionPerformed(ActionEvent a){
            sequencer.stop();
        }
    }

    public class MyUpTempoListener implements ActionListener{
        public void actionPerformed(ActionEvent a){
            float tempoFactor = sequencer.getTempoFactor();
            sequencer.setTempoFactor((float)(tempoFactor * 1.03));
        }
    }

    public class MyDownTempoListener implements ActionListener{
        public void actionPerformed(ActionEvent a){
            float tempoFactor = sequencer.getTempoFactor();
            sequencer.setTempoFactor((float)(tempoFactor * .97));
        }
    }

    public void makeTracks(int[] list){

        for(int i = 0; i < 16; i++){
            int key = list[i];

            if(key != 0){
                track.add(makeEvent(144,9,key,100,i));
                track.add(makeEvent(128,9,key,100,i+1));
            }
        }
    }

    public MidiEvent makeEvent(int comd, int chan, int one, int two, int tick){
        MidiEvent event = null;
        try{
            ShortMessage a = new ShortMessage();
            a.setMessage(comd, chan, one, two);
            event = new MidiEvent(a, tick);
        }catch(Exception e) {e.printStackTrace();}
        return event;
    }
}
import java.awt.*;
导入javax.swing.*;
导入javax.sound.midi.*;
导入java.util.*;
导入java.awt.event.*;
公共类BeatBox{
JPanel主面板;
ArrayList复选框列表;
测序器;
序列;
轨道;
JFrame框架;
String[]instrumentNames={“低音鼓”、“高帽闭合”,
“打开Hi-Hat”、“原声圈套”、“撞击钹”、“鼓掌”,
“High Tom”、“High Bongo”、“Maracas”、“Whistle”、“Low Conga”,
“开高康加”};
国际[]文书={35,42,46,38,49,39,50,60,70,72,64,56,58,47,67,63};
公共静态void main(字符串[]args){
BeatBox=新BeatBox();
buildGUI();
}
public void buildGUI(){
theFrame=新JFrame(“赛博BeatBox”);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
BorderLayout=新的BorderLayout();
JPanel背景=新JPanel(布局);
background.setboorder(BorderFactory.createEmptyBorder(10,10,10,10));
checkBoxList=newarraylist();
框按钮框=新框(框布局Y_轴);
JButton start=新JButton(“start”);
start.addActionListener(新的MyStartListener());
按钮盒。添加(开始);
JButton stop=新JButton(“stop”);
addActionListener(新的MyStopListener());
按钮盒。添加(停止);
JButton upTempo=新JButton(“节拍上升”);
addActionListener(新的myuptempolListener());
按钮盒。添加(upTempo);
JButton downTempo=新JButton(“Tempo Down”);
addActionListener(新的MyDownTempoListener());
按钮盒。添加(下拍子);
盒子名称盒子=新盒子(盒子布局Y_轴);
对于(int i=0;i<16;i++){
添加(新标签(仪器名称[i]);
}
添加(BorderLayout.EAST,buttonBox);
添加(BorderLayout.WEST,nameBox);
theFrame.getContentPane().add(后台);
GridLayout网格=新的GridLayout(20,20);
网格设置间隙(1);
网格setHgap(2);
主面板=新的JPanel(网格);
添加(BorderLayout.CENTER,主面板);
对于(int i=0;i<256;i++){
JCheckBox c=新的JCheckBox();
c、 已选择(假);
复选框列表。添加(c);
主面板。添加(c);
}
setUpMidi();
机架立根(50,50300300);
frame.pack();
frame.setVisible(true);
}
公共无效设置MIDI(){
试一试{
sequencer=MidiSystem.getSequencer();
sequencer.open();
序列=新序列(sequence.PPQ,4);
track=sequence.createTrack();
sequencer.setTempoInBPM(120);
}catch(异常e){e.printStackTrace();}
}
public void buildTrackAndStart(){
int[]trackList=null;
顺序。删除跟踪(跟踪);
track=sequence.createTrack();
对于(int i=0;i<16;i++){
trackList=newint[16];
int键=仪器[i];
对于(int j=0;j<16;j++){
JCheckBox jc=(JCheckBox)checkBoxList.get(j+(16*i));
if(jc.isSelected()){
trackList[j]=键;
}否则{
轨迹列表[j]=0;
}
}
makeTracks(trackList);
track.add(makeEvent(176,1127,0,16));
}
添加(makeEvent(192,9,1,0,15));
试一试{
序列器。设置序列(序列);
sequencer.setLoopCount(sequencer.LOOP_连续);
sequencer.start();
sequencer.setTempoInBPM(120);
}catch(异常e){e.printStackTrace();}
}
公共类MyStartListener实现ActionListener{
已执行的公共无效操作(操作事件a){
buildTrackAndStart();
}
}
公共类MyStopListener实现ActionListener{
已执行的公共无效操作(操作事件a){
sequencer.stop();
}
}
公共类MyUpTempoListener实现ActionListener{
已执行的公共无效操作(操作事件a){
float tempoFactor=sequencer.getTempoFactor();
sequencer.setTempoFactor((浮点)(tempoFactor*1.03));
}
}
公共类MyDownTempoListener实现ActionListener{
已执行的公共无效操作(操作事件a){
float tempoFactor=sequencer.getTempoFactor();
sequencer.setTempoFactor((浮点)(tempoFactor*.97));
}
}
公共void生成跟踪(int[]列表){
对于(int i=0;i<16;i++){
int key=list[i];
如果(键!=0){
添加(makeEvent(144,9,key,100,i));
添加(makeEvent(128,9,key,100,i+1));
}
}
}
公共MidiEvent生成事件(int comd、int chan、int one、int two、int tick){
MidiEvent=null;
试一试{
短消息a=新短消息();
a、 设置消息(comd、chan、一、二);
事件=新事件(a,勾号);
}catch(异常e){e.printStackTrace();}
返回事件;
}
}
这是:

for(int i = 0; i < 16; i++) {
    nameBox.add(new Label(instrumentNames[i]));
}
或者,对于每个循环:

for (String instrumentName : instrumentNames) {
    nameBox.add(new Label(instrumentName));
}

非常感谢。多一双眼睛很好。当计时器启动时,将标记为应答。。。我跳过了代码示例中的一整行仪器名称。很高兴能提供帮助!最好避免在这样的循环中使用硬编码限制。使用一个常量,数组的大小,或者在可能的情况下迭代使用。
for (String instrumentName : instrumentNames) {
    nameBox.add(new Label(instrumentName));
}