如何使用Java代码---将文件转换为字符串呢?

文件读取并转换为字符串的实现思路：
    方式1:
	  使用Files.readString方法即可将一个文件读取为字符串
    方式2:
	  使用Files.lines或Files.readAllLines读取,然后再聚合
	方式3:
	  使用Apache Commons IO中FileUtils.readFileToString方法即可将文件读取为字符串

Java 11 – Files.readString

package com.java265;
 
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
 
public class FileToString1 {
    public static void main(String[] args) {
        String path = "d:\\test\\test.log";
        try {
            // default StandardCharsets.UTF_8
            String content = Files.readString(Paths.get(path));
            System.out.println(content);
 
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Java 8 – Files.lines

将文件转换为Stream并加入 

package com.java265;
 
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.stream.Collectors;
import java.util.stream.Stream;
 
public class FileToString2 {
 
    public static void main(String[] args) {
 
        String path = "d:\\test\\test.log";
 
        try (Stream<String> lines = Files.lines(Paths.get(path))) {
 
            // Formatting like \r\n will be lost
            // String content = lines.collect(Collectors.joining());
 
            // UNIX \n, WIndows \r\n
            String content = lines.collect(Collectors.joining(System.lineSeparator()));
            System.out.println(content);
 
			// File to list
            //List<String> list = lines.collect(Collectors.toList());
 
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Java 7 – Files.readAllLines

package com.java265;
 
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.List;
public class FileToString3 {
    public static void main(String[] args) {
        String path = "d:\\test\\test.log";
        try {
 			// Java 7
            List<String> content = Files.readAllLines(Paths.get(path), StandardCharsets.UTF_8);
 
            System.out.println(content);
 
        } catch (IOException e) {
            e.printStackTrace();
        }
 
    }
 
}

Apache Commons IO

pom.xml
<dependency>
		<groupId>commons-io</groupId>
		<artifactId>commons-io</artifactId>
		<version>2.6</version>
	</dependency>


package com.java265;
import org.apache.commons.io.FileUtils;
import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
public class FileToString4 {
    public static void main(String[] args) {
        String path = "d:\\test\\test.log";
        try {
            String content = FileUtils.readFileToString(new File(path), StandardCharsets.UTF_8);
            System.out.println(content);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}