EditText输入自动空格

package cn.juzhong.util;

import android.text.Editable;
import android.text.Selection;
import android.text.TextWatcher;
import android.widget.EditText;

public class EditTextUtil implements TextWatcher{
private int beforeTextLength = 0; //输入前的长度
private int onTextLength = 0; //文字的长度
private boolean isChanged = false;
private int location = 0;//记录光标的位置
private char[] tempChar;
private StringBuffer buffer = new StringBuffer();
private int blankNumber = 0;
private EditText editText;

public EditTextUtil(EditText text){
editText = text;
}

@Override
public void afterTextChanged(Editable arg0) {
// TODO Auto-generated method stub
if(isChanged){
location = editText.getSelectionEnd();
int index = 0;
while (index < buffer.length()) {
if (buffer.charAt(index) == ' ') {
buffer.deleteCharAt(index);
} else {
index++;
}
}

index = 0;
int konggeNumberC = 0;
while (index < buffer.length()) {
if ((index == 4 || index == 9 || index == 14 || index == 19)) {
buffer.insert(index, ' ');
konggeNumberC++;
}
index++;
}

if (konggeNumberC > blankNumber) {
location += (konggeNumberC - blankNumber);
}

tempChar = new char[buffer.length()];
buffer.getChars(0, buffer.length(), tempChar, 0);
String str = buffer.toString();
if (location > str.length()) {
location = str.length();
} else if (location < 0) {
location = 0;
}

editText.setText(str);
Editable etable = editText.getText();
Selection.setSelection(etable, location);
isChanged = false;
}
}

@Override
public void beforeTextChanged(CharSequence text, int arg1, int arg2,
int arg3) {
// TODO Auto-generated method stub
beforeTextLength = text.length();
if(buffer.length() > 0){
buffer.delete(0, buffer.length());
}

blankNumber = 0;
for(int i = 0;i < text.length();i ++){
if(text.charAt(i) == ' '){
blankNumber ++;
}
}
}

@Override
public void onTextChanged(CharSequence text, int arg1, int arg2, int arg3) {
// TODO Auto-generated method stub
onTextLength = text.length();
buffer.append(text.toString());
if(onTextLength == beforeTextLength || onTextLength <= 3
|| isChanged){
isChanged = false;
return;
}

isChanged = true;
}

}

bankNumberEditText.addTextChangedListener(new EditTextUtil(bankNumberEditText));