自己做的J2ME閱讀器原始碼！
挺長時間沒有更新Blog，因為內容不多，所以總結起來一起更新。
這個東西做了十多天，別人可能也就1天左右，為什麼我要那麼長？可能是新手的原因吧，而且這段時間課程也比較緊。廢話不說。程式碼上來：
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.Vector;
import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Graphics;
import javax.microedition.midlet.MIDlet;
public class newCanvas extends Canvas implements CommandListener{
private String s; //把讀出來的位元組碼形成UTF-8編碼方式
private final static int scrHight = 208; //固定的螢幕高度。
private Font f; //當前系統預設字型資訊
private char[] c; //通過s得到的char陣列
private Vector view; //最後形成，存放文字的地方
private String[] strView; //顯示用陣列
private int start; //顯示的開始行
private int end; //終止行
private int scrLines; //螢幕可以列印多少行
public static MIDlet mid; //主視窗
//成員變數初始化
public newCanvas() {
setFullScreenMode(true);
s = null;
f = Font.getDefaultFont();
c = null;
view = new Vector();
try {
s = getText(); //測試通過，已經得到檔案內容。
} catch (IOException e) {
System.out.println("讀檔案失敗！"); //這裡新增錯誤處理
}
c = s.toCharArray();
cut(view, c);
strView = new String[view.size()];
scrLines = scrHight / f.getHeight(); //scrHight
start = 0;
end = scrLines;
//按行存放到陣列中，方便以後顯示。
Enumeration e = view.elements();
for (int i = 0; i < strView.length; i++) {
strView[i] = (String) e.nextElement();
}
//垃圾回收
s = null;
System.gc();
//新增退出命令
this.addCommand(new Command("退出", Command.EXIT, 1));
setCommandListener(this);
}
public void paint(Graphics g) {
clearScreen(g);
int x = 0;
int y = -f.getHeight();
for (int i = start; i <= end - 1; i++) {
y += f.getHeight();
g.drawString(strView[i], x, y, f.SIZE_SMALL);
}
}
private void clearScreen(Graphics g) {
g.setColor(255, 255, 255);
g.fillRect(0, 0, getWidth(), scrHight); //scrHight
g.setColor(0, 0, 0);
}
public String getText() throws IOException {
InputStream is = getClass().getResourceAsStream("/1.txt");
is.skip(3); //跳過UTF-8的標記符號
if (null != is) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
int ch = 0;
while ((ch = is.read()) != -1) {
baos.write(ch);
}
byte[] text = baos.toByteArray();
baos.close();
return new String(text, "UTF-8");
} else {
return null;
}
}
public void cut(Vector v, char[] c) {
StringBuffer sb = new StringBuffer(); //臨時存放一行內容的容器
int tmp = 0; //記錄截斷位
int num = 0; // 行內數字計數器
while (tmp < c.length - 1) {
for (int i = tmp; i < c.length; i++) {
if (c[i] == '/n') {
num = 0;
tmp++; //遇到空格跳過去
break;
}
num += f.charWidth(c[i]); //記錄開始
if (num >= getWidth()) {
num = 0;
tmp++; //重複字元跳過去。
break;
}
sb.append(c[i]); // 新增字元
tmp = i;
}
v.addElement(sb.toString());
sb.delete(0, sb.length());
}
sb = null; //清理垃圾
}
protected void keyPressed(int keycode) {
switch (getGameAction(keycode)) {
case Canvas.UP:
if (start == 0) {
break;
}
start = start - 1;
end = end - 1;
repaint();
break;
case Canvas.DOWN:
if (end == strView.length) {
break;
}
start = start + 1;
end = end + 1;
repaint();
break;
case Canvas.LEFT:
if ((start - (scrLines - 1)) < 0) {
start = 0;
end = scrLines;
repaint();
break;
}
start = start - (scrLines - 1);
end = end - (scrLines - 1);
repaint();
break;
case Canvas.RIGHT: //對右鍵的處理，是向下翻一頁。
if ((end + (scrLines - 1)) >= strView.length) {
if (end == strView.length) {
break;
}
start = end;
end = strView.length;
repaint();
break;
}
start = start + (scrLines - 1);
end = end + (scrLines - 1);
repaint();
break;
}
}
public void commandAction(Command c, Displayable d) {
if (c.getLabel().equals("退出")) {
mid.notifyDestroyed();
}
}
}
要讀的檔案放到res目錄裡，必須是UTF-8格式的。
這個程式只是能跑起來，速度不是很快，需要把演算法在優化一下，這幾天就弄，然後再加點功能。