springboot之json/yml配置文件的读取
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配置文件读取
项目根目录的config目录下person.yml, 文件夹如下
person:
name: qinjiang
age: 3
happy: false
birth: 2000/01/01
maps: {k1: v1, k2: v2}
lists:
- code
- girl
- music
dog:
name: 旺财
age: 1
device.json文件
{
"id": 23,
"name": "robot",
"state": 2,
"point": [
1,
2
]
}
单个注入: @Value
可用于json/yml文件
@Component
@PropertySource(value = {"file:./config/person.yml"},factory = YamlPropertySourceFactory.class)
@PropertySource(value = {"file:./config/device.json"})
public class Cat {
@Value("${person.dog.name}")
@value(${id}) // device.json文件中的字段
private String name;
@Bean
public void testValue(){
System.out.println("field name is injected through @Value:" + name);
}
}
________________________________________
field name is injected through @Value:旺财
批量注入: @ConfigurationProperties注解
yml文件
这个注解常用于yml文件, 可以通过@PropertySource注解指定配置文件的路径. 其中file:./config/person.yml表示的项目的根路径下的文件夹config下文件person,.yml, 可以发现它是按名字匹配的.
package com.wang.yml;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.beans.factory.config.YamlPropertiesFactoryBean;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.context.properties.ConfigurationPropertiesScan;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.PropertySource;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
import java.util.Date;
import java.util.List;
import java.util.Map;
/**
* Person : TODO
*
* @author : Wangwenchu
* @since : 2023/1/12
*/
@Data
@Component
@ConfigurationProperties(prefix = "person")
@PropertySource(value = {"file:./config/person.yml"},factory = YamlPropertySourceFactory.class)
public class Person {
private String name;
private Integer age;
private Boolean happy;
private Date birth;
private Map<String,Object> maps;
private List<Object> lists;
private Dog dog;
}
@Data
public class Dog {
private String name;
private int age;
}
-------------------------------------
Person(name=qinjiang, age=3, happy=false, birth=Sat Jan 01 00:00:00 CST 2000,
maps={k1=v1, k2=v2}, lists=[code, girl, music], dog=Dog(name=旺财, age=1))
其中YamlPropertySourceFactory为:
package com.wang.yml;
import org.springframework.beans.factory.config.YamlPropertiesFactoryBean;
import org.springframework.core.env.PropertiesPropertySource;
import org.springframework.core.env.PropertySource;
import org.springframework.core.io.support.EncodedResource;
import org.springframework.core.io.support.PropertySourceFactory;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Properties;
/**
/ * YamlPropertySourceFactory : TODO
*
* @author : Wangwenchu
* @since : 2023/1/13
*/
public class YamlPropertySourceFactory implements PropertySourceFactory {
@Override
public PropertySource<?> createPropertySource(String sourceName, EncodedResource resource) throws IOException {
Properties propertiesFromYaml = loadYaml(resource);
if(sourceName == null || sourceName.length() == 0){
sourceName = resource.getResource().getFilename();;
}
return new PropertiesPropertySource(sourceName, propertiesFromYaml);
}
private Properties loadYaml(EncodedResource resource) throws FileNotFoundException {
try {
YamlPropertiesFactoryBean factory = new YamlPropertiesFactoryBean();
factory.setResources(resource.getResource());
factory.afterPropertiesSet();
return factory.getObject();
} catch (IllegalStateException e) {
// for ignoreResourceNotFound
Throwable cause = e.getCause();
if (cause instanceof FileNotFoundException)
throw (FileNotFoundException) e.getCause();
throw e;
}
}
}
补充
- file: ./config 工程根目录下config目录
- classpath:/config/ jar包内的文件目录, 对应于resource目录
json文件读取
导入fastjson的maven依赖:
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
</dependency>
常用的操作
获取单个属性
以下面的device.json为例:
{
"id": 23,
"name": "robot",
"state": 2,
"point": [
1,
2
]
}
- json path -- > File --> String --> JSONObject --> 调用getString(name)
public void getPropertyFromObject() {
String path = System.getProperty("user.dir") + File.separator + "config" + File.separator + "device.json";
File file = new File(path);
try {
String json = FileUtils.readFileToString(file);
JSONObject jsonObject = JSONObject.parseObject(json);
System.out.println("name:" + jsonObject.getString("name"));
} catch (IOException e) {
throw new RuntimeException(e);
}
}
_________________________
name:robot
JSON.parseObject实现转为, 注意也是按照属性名和配置文件中的相匹配(大小写忽略), 没有的字段为null, 存在的就注入
public void getObject() {
String path = System.getProperty("user.dir") + File.separator + "config" + File.separator + "device.json";
File file = new File(path);
try {
String json = FileUtils.readFileToString(file);
Robot config = JSON.parseObject(json,Robot.class);
System.out.println(config.getId());
System.out.println(config.getName());
System.out.println(config.getState());
System.out.println(config.getCode()); // null
System.out.println(config.getPoint().get(0));
} catch (IOException e) {
throw new RuntimeException(e);
}
}
___________________
23
robot
2
null
1
object-->jsonString
public static void obj2JsonStr() {
Robot robot = new Robot();
robot.setId("001");
robot.setName("v7");
robot.setPoint(Arrays.asList(new String[]{"a", "b"}));
robot.setCode("err");
robot.setState(0);
String jsonStr = JSON.toJSONString(robot);
System.out.println(jsonStr);
}
-----------------------------
{"code":"err","id":"001","name":"v7","point":["a","b"],"state":0}
list(object)-->jsonString
public static void listObj2JsonStr() {
Robot robot1 = new Robot();
robot1.setId("001");
robot1.setName("v7");
robot1.setPoint(Arrays.asList(new String[]{"a", "b"}));
robot1.setCode("err");
robot1.setState(0);
Robot robot2 = new Robot();
robot2.setId("002");
robot2.setName("v3");
robot2.setPoint(Arrays.asList(new String[]{"e", "c"}));
robot2.setCode("ok");
robot2.setState(1);
List<Robot> list = new ArrayList<>();
list.add(robot1);
list.add(robot2);
String jsonStr = JSON.toJSONString(list);
System.out.println(jsonStr);
}
_________________________
[{"code":"err","id":"001","name":"v7","point":["a","b"],"state":0},{"code":"ok","id":"002","name":"v3","point":["e","c"],"state":1}]
Map-->json
public static void mapToJson() {
Robot robot = new Robot();
robot.setId("001");
robot.setName("v7");
robot.setPoint(Arrays.asList(new String[]{"a", "b"}));
robot.setCode("err");
robot.setState(0);
Map<String, Robot> map = new HashMap<>();
map.put("rb1", robot);
// {"rb1":{"code":"err","id":"001","name":"v7","point":["a","b"],"state":0}}
String jsonStr = JSON.toJSONString(map);
System.out.println(jsonStr);
}
json --> object
public static void json2Object() {
String path = System.getProperty("user.dir") + "/config/rb.json";
File file = new File(path);
String jsonStr = null;
try {
jsonStr = FileUtil.readAsString(file);
} catch (IOException e) {
throw new RuntimeException(e);
}
Robot robot = JSONObject.parseObject(jsonStr, Robot.class);
System.out.println(robot.toString());
}
json --> List(Object)
[
{
"code": "err",
"id": "002",
"name": "v1",
"point": [
"a",
"b"
],
"state": 0
},
{
"code": "err",
"id": "002",
"name": "v2",
"point": [
"a",
"b"
],
"state": 0
}
]
public static void json2ObjectList() {
String path = System.getProperty("user.dir") + "/config/rbs.json";
File file = new File(path);
String jsonStr = null;
try {
jsonStr = FileUtil.readAsString(file);
} catch (IOException e) {
throw new RuntimeException(e);
}
List<Robot> list = JSON.parseArray(jsonStr, Robot.class);
System.out.println(list);
}
json --> Map
{
"rb1": {
"code": "err",
"id": "002",
"name": "v1",
"point": [
"a",
"b"
],
"state": 0
},
"rb2": {
"code": "err",
"id": "002",
"name": "v2",
"point": [
"a",
"b"
],
"state": 0
}
}
public static void json2Map() {
String path = System.getProperty("user.dir") + "/config/rbMap.json";
File file = new File(path);
String jsonStr = null;
try {
jsonStr = FileUtil.readAsString(file);
} catch (IOException e) {
throw new RuntimeException(e);
}
Map<String, Robot> map = JSON.parseObject(jsonStr, new TypeReference<Map<String, Robot>>(){});
// rb1->Robot(id=002, name=v1, state=0, code=err, point=[a, b])
// rb2->Robot(id=002, name=v2, state=0, code=err, point=[a, b])
map.forEach((id, value) -> {
System.out.println(id + "->" + value);
});
}
