4.整型或其他類型與字符串類型的相互轉(zhuǎn)換殖蚕。
int a = Integer.parseInt(String s)
5.寫到文件中：
static private int freqShink(String freqFileName, int freq){
int return_value = -1;
FileInputStream fin = null;
FileWriter writer = null;
File cpu_scaling_file = new File(freqFileName);
try{
fin = new FileInputStream(cpu_scaling_file);
int length = fin.available();
byte [] buffer = new byte[length];
fin.read(buffer);
String res = new String(buffer);
int old_freq = Integer.parseInt(res.trim()); //文件中內(nèi)容讀到byte數(shù)組妈候，轉(zhuǎn)為字符串如蚜，再?gòu)闹修D(zhuǎn)為整型
writer = new FileWriter(freqFileName);
writer.write(Integer.toString(freq).toCharArray()); //將整型轉(zhuǎn)為字符串，再轉(zhuǎn)為字符數(shù)組寫到文件中
if(DEBUG){Log.i(TAG, freqFileName + ", change from " + old_freq + " to " + freq);}
}catch(Exception e){
Log.e(TAG, e.toString());
Log.e(TAG, "Can't change the cpu freq: " +
freqFileName +
", ignore it.");
}finally{
if (fin != null) {
try {
fin.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (writer != null) {
try {
writer.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return return_value;
}
8.常用的正則表達(dá)式：如
public static boolean isNumeric(String str){ //是數(shù)字返回true
Pattern pattern = Pattern.compile("[0-9]*");
return pattern.matcher(str).matches();
}
private boolean ifLegal(String motorID){
char c = motorID.charAt(0);
String sub= motorID.substring(1);
if (isNumeric(sub) && !Character.isLowerCase(c)){ //判斷大寫字母
return true;
}
return false;
}
9.創(chuàng)建自己需要的簡(jiǎn)單的類：
如：
public class Point{
private int pointX,pointY;
public Point(int x,int y){
pointX=x;
pointY=y;
}
public void putPointX(int point){
pointX = point;
}
public int getPointX(){
return pointX;
}
public void putPointY(int point){
pointY = point;
}
public int getPointY(){
return pointY;
}
}