The special prefix classpath*:` enables loading **all** matching resources across entire classpath。which is indispensable for batch configuration or template loading.
三、常用资源位置前缀与痛点对应方法
classpath: 前缀 — “找不到配置文件”痛点方法
If a resource is placed under /src/main/resources/config/…/app.properties,you can reliably load it via:
@Service
public class ConfigLoader {
private final ResourceLoader resourceLoader;public ConfigLoader {
this.resourceLoa der =resourceL oader;}
public Properties loadProperties throws IOExc eption{
Resource r=resourceLoa der .getRes ource;Properties p=new Properties;p.load)，说起来，return p;}
}
2. 方法常量 + 配置属性组合 – 把“硬编码”彻底根除
常量类示例
public final class Res ourcePaths{
private Resour cePaths{}
// 配置目录
public static final String CONF IG_DIR ="classpath :config/";public static final String APP_PRO PERTS =CONF IG_DIR+ "app.properti es";
// 模板目录
public static final String TEMPL ATES_DI R ="class path :templates/";}
@ConfigurationProperties
public record Resour ceProperties(
String configDir,String templatesDir,String fileDir){
public String configOf{
return configDir+name;}
}
4. 封装统一资源服务 – 所有业务只调用 Service 方法即可
@Service
public class Res ourceService{
private final Res ourceLoa der;private final Resour ceProperties props;publ ic Re sourceService(Res ourceLoad er lo ad er,Re sour ceProperties pr ops){
this.resourceL oader= loader;this.props=pr ops;}
/** 读取 properties 文件 */
public Properties loadProp throws IOExcep tion{
Resource r=resourceL oader.ge tRes ource);Properties p=new Pro perties;try){
p.load;}
return p，}
/** 读取文本模板 */
public String readTemplate throws IOE xception{
Resource r=resourceL oader.ge tRes ource+relativePath);try){
return new St ring,StandardCharsets.UTF_8);}
}
/** 批量加载符合 Ant 模式的模板 */
public Map loadTemplates throws IOE xception{
Map map=new Ha shMap<>;Resource arr=resourceL oader)
.getResources+pattern);for{
try){
map.put,new St ring。StandardCharsets.UTF_8));}
}
return map;}
/** 检查任意方法是否存在 */
public boolean exists{
return resourceL oader.ge tRes ou rce.exi sts;}
}
@Service
public clas s TemplateManager{
private final Res ourceServi ce rs;pub lic TemplateMan ager{
this.rs=rs;}
/** 加载所有 HTML 邮件模板 */
public Map loadAllEmailTemplatesthrows IOEx cep tion{
return rs.loadTemplates;}
}
// 调用方
@RestController
@Req uestMapping
publi c class MailCtrl{
private final Tem plateManag er tm;pub lic MailCtrl{
this.tm=tm;}
@GetMapping
publ ic ResponseEntity welcome{
try{
String tpl=tm.loadAllEmailTemplates
.get;return Resp onseEntity.ok;}catch{
return Resp onseEntity.status
.body;}
}
}
6. 轻量级工具类
public final class Re sourc eUtils{
private static Re sourc ePatternResolver resolver;
// 在启动时由 Spring 注入一次即可
pub lic static void setResolver{
resolver=r;}
/** 将任意资源读取为字符串 */
pub lic static Stri ng readAsStringthrows IOExcep tion{
Resou rce res=resol ver.ge tRes ource;try){
return new Str ing,StandardCharsets.UTF_8);}
}
/** 返回匹配到的所有资源完整方法 */
pub lic static List listResourcesthrows IOE xception{
Resou rce arr=resolv er.ge tResources;retu rn Arrays.stre am
.map.toString;}
catch{retur n "";}
})
.collect);}
}
// 配置类中一次性完成注入
@Configuration
pub lic clas s Resour ceConfig{
@Bean
pu blic Re sourc eUtils initUtil{
Re sourc eUtils.setResolver;retu rn new Re sourc eUtils;// 不需要实例，只是触发 bean 创建
}
}
// 使用示例
Strin g tpl=Re sourc eU til s.rea dAsString;Lista llCon figFiles=
Re sou rc eU til s.li stResources;话说回来，
