Java 读取文件全部内容

主要代码：

import java.io.File;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;

public class Application {
    public static void main(String[] args) throws IOException {
        String content = "";
        StringBuilder builder = new StringBuilder();

        File file = new File("E:\\hello.txt");
        InputStreamReader streamReader = new InputStreamReader(new FileInputStream(file), StandardCharsets.UTF_8);
        BufferedReader bufferedReader = new BufferedReader(streamReader);

        while ((content = bufferedReader.readLine()) != null) 
            builder.append(content);

        System.out.println(builder.toString());
    }
}