java中读取资源文件 java读取resources下的文件

1. 使用项目内路径读取，该路径只在开发工具中显示，如：src/main/resources/resource.properties。只能在开发工具中使用，部署之后无法读取。（不通用）

public void read() throws IOException {
	File file = new File("src/main/resources/resource.properties");
	FileInputStream fis = new FileInputStream(file);
	InputStreamReader isr = new InputStreamReader(fis);
	BufferedReader br = new BufferedReader(isr);
	String data = null;
	while((data = br.readLine()) != null) {
		System.out.println(data);
	}
	
	br.close();
	isr.close();
	fis.close();
}

2. 使用org.springframework.util.ResourceUtils读取，在linux环境中无法读取。（不通用）

public void read2() throws IOException {
	File file = ResourceUtils.getFile("classpath:resource.properties");
	FileInputStream fis = new FileInputStream(file);
	InputStreamReader isr = new InputStreamReader(fis);
	BufferedReader br = new BufferedReader(isr);
	String data = null;
	while((data = br.readLine()) != null) {
		System.out.println(data);
	}
	
	br.close();
	isr.close();
	fis.close();
}

3. 使用org.springframework.core.io.ClassPathResource, 各环境都能读取。（通用）

public void testReadFile() throws IOException {
	//  ClassPathResource classPathResource = new ClassPathResource("resource.properties");
	Resource resource = new ClassPathResource("resource.properties");
	InputStream is = resource.getInputStream();
	InputStreamReader isr = new InputStreamReader(is);
	BufferedReader br = new BufferedReader(isr);
	String data = null;
	while((data = br.readLine()) != null) {
		System.out.println(data);
	}
	
	br.close();
	isr.close();
	is.close();
}

4. 结合spring注解，使用org.springframework.core.io.ResourceLoader。（通用）

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class ApplicationTests {

    @Autowired
    ResourceLoader resourceLoader;
    
    
    @Test
    public void testReaderFile() throws IOException {
        Resource resource = resourceLoader.getResource("classpath:resource.properties");
        InputStream is = resource.getInputStream();
        InputStreamReader isr = new InputStreamReader(is);
        BufferedReader br = new BufferedReader(isr);
        String data = null;
        while((data = br.readLine()) != null) {
            System.out.println(data);
        }
        
        br.close();
        isr.close();
        is.close();
    }

}