网上找了很久都找不到想要的工具类，索性自己写了一个。原理就是吧 每行中的第一个等于号=，换成特殊字符串，然后进行分割，读取。遇到#符号停止读取，转到下一行读取。
直接上案例
下面是测试的文件test.txt
##注释##
#注释
time=2020/7/25
name= KL-Skeleton
array= 1,2,3,4,五,六,七,8,9,0
#注释####
age= 20
height= 199.999
blog_name=JAVA 【基础】 properties配置文件的读取和修改 （不会删除注释）
#注释####
测试用例
public class main {
public static void main(String[] args) {
//传入路径，初始化配置文件，
LoadProperties load = new LoadProperties("bin/test.txt");
System.out.println(load.map.toString());
//读取数据
System.out.println(load.getString("time"));
System.out.println(load.get("name"));
System.out.println(load.getInt("age"));
System.out.println(load.getDouble("height"));
System.out.println(load.getString("blog_name"));
System.out.println(load.getBoolean("over_read"));
//更新数据
load.upDate("name","新名字2222");
System.out.println(load.get("name"));
//删除数据
load.delete("height");
//增加数据
load.add("height","22222");
}
}
输出：（String类不会替换空格，其他类型强制替换，防止转换出错）
运行过后。注释不会删除
源码：
import java.io.*;
import java.util.HashMap;
import java.util.Map;
/**
* @Author: KL-Skeleton
* @Description: 只要是文件都行， setting.ini 或 setting.properties 都是可以使用这个类的，格式一定要key=value 。注释要用#
* @Date: Created in 15:44 2020/6/29
*/
public class PropertiesUtil {
public String url = "bin/setting.ini";//设置默认的读取文件
Map<Object,Object> map = new HashMap<>();
PropertiesUtil(){
read();
}
PropertiesUtil(String url){
this.url = url;
read(url);
}
//更新数据
public void upDate(String key, String valuse) {
String data=setReadFileListener(new ReadFileListener() {
@Override
String setLine(String line) {
if(!line.equals("") ){
String data="";
String string[] = line.replaceFirst("=","#=#").split("#=#");
if(string.length!=0){
String keystr = string[0].replaceAll("\\s*","");
if (keystr.equals(key)&& !line.contains("#")) {
data += key + "=" + valuse + "\n" ;
} else {
data += line + "\n";
}
}
return data;
}else return "";
}
});
saveData(data);
}
//读取默认的url配置文件
public void read() {
read(url);
}
public void read(String url) {
setReadFileListener(new ReadFileListener() {
@Override
String setLine(String line) {
if(line.contains("#"))line=line.split("#")[0];//不读取注释
if (!line.equals("")) {
String string[] = line.replaceFirst("=","#=#").split("#=#");//替换等号为特殊字符串#=#，然后分割（这里任意都行，只要不存在歧义）
if(string!=null){
map.put(string[0], string[1]);
}
}
return "";
}
});
}
//删除数据
public void delete(String key){
String data=setReadFileListener(new ReadFileListener() {
@Override
String setLine(String line) {
if(!line.equals("")){
String data="";
String string[] = line.replaceFirst("=","#=#").split("#=#");
if(string.length!=0){
String keystr = string[0].replaceAll("\\s*","");
if(keystr.equals(key));
else data+=line+"\n";
}
return data;
}else return "";
}
});
saveData(data);
}
//添加数据
public void add(String key,String value){
File file = new File(url);
try {
FileWriter fileWriter = new FileWriter(file,true);
fileWriter.write("\n"+key+"="+value);
fileWriter.flush();
fileWriter.close();
} catch (IOException e) {
e.printStackTrace();
}
}
//设置文件读取的监听器，每读取一行数据，返回一次回调函数
private String setReadFileListener(ReadFileListener readFileListener){
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader(new File(url)));
String tempstr = "";
String data="";
while ((tempstr = reader.readLine()) != null) {
data+= readFileListener.setLine(tempstr);
}
return data;
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return null;
}
private void saveData(String data){
try {
FileWriter writer = new FileWriter(url);
// 向文件写入内容
writer.write(data);
writer.flush();
writer.close();
}catch (IOException e){
e.printStackTrace();
}
//修改完成后，重新读取，刷新数据
read();
}
public String getString(String key){
return String.valueOf(map.get(key));
}
public int getInt(String key){
return Integer.valueOf(String.valueOf(map.get(key)).replaceAll("\\s*",""));
}
public double getDouble(String key){
return Double.valueOf(String.valueOf(map.get(key)).replaceAll("\\s*",""));
}
public boolean getBoolean(String key){
return Boolean.valueOf(String.valueOf(map.get(key)).replaceAll("\\s*",""));
}
public Object get(Object key){
return map.get(key);
}
public String[] getStrings(String key){
return getString(key).split(",");
}
public int[] getInts(String key){
return StringToInt(getString(key).split(","));
}
public Object[] getObjects(String key){
return StringToObject(getString(key).split(","));
}
public int[] StringToInt(String[] arrs){
int[] ints = new int[arrs.length];
for(int i=0;i<arrs.length;i++){
ints[i] = Integer.parseInt(arrs[i]);
}
return ints;
}
public Object[] StringToObject(String[] arrs){
Object[] ints = new Object[arrs.length];
for(int i=0;i<arrs.length;i++){
ints[i] = (Object)arrs[i];
}
return ints;
}
}
abstract class ReadFileListener {
String setLine(String line){
return "";};
}