java list 写入文件夹_java怎么将list里的内容写入文件,和从文件中读取?
时间: 2023-11-07 15:11:18 浏览: 40
要将Java中的List写入文件夹,可以使用Java IO库中的FileWriter和BufferedWriter类,如下所示:
```java
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.List;
public class WriteListToFile {
public static void writeListToFile(List<String> list, String fileName) {
try (BufferedWriter writer = new BufferedWriter(new FileWriter(fileName))) {
for (String s : list) {
writer.write(s);
writer.newLine();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
```
这个方法将List中的每个字符串写入文件中,每个字符串占据一行。要从文件中读取List,可以使用Java IO库中的FileReader和BufferedReader类,如下所示:
```java
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class ReadListFromFile {
public static List<String> readListFromFile(String fileName) {
List<String> list = new ArrayList<>();
try (BufferedReader reader = new BufferedReader(new FileReader(fileName))) {
String line;
while ((line = reader.readLine()) != null) {
list.add(line);
}
} catch (IOException e) {
e.printStackTrace();
}
return list;
}
}
```
这个方法从文件中读取每一行字符串,并将其存储到List中返回。