@ComponentScan 详解
作者：互联网
@ComponentScan
1 @Retention(RetentionPolicy.RUNTIME)
2 @Target(ElementType.TYPE)
3 @Documented
4 @Repeatable(ComponentScans.class)
5 public @interface ComponentScan {
6
7 /**
8 * 扫描路径
9 * @ComponentScan(value = "spring.annotation.componentscan")
10 */
11 @AliasFor("basePackages")
12 String[] value() default {};
13
14 /**
15 * 扫描路径
16 */
17 @AliasFor("value")
18 String[] basePackages() default {};
19
20 /**
21 * 指定扫描类
22 * @ComponentScan(basePackageClasses = {BookDao.class, BookService.class})
23 */
24 Class<?>[] basePackageClasses() default {};
25
26 /**
27 * 命名注册的Bean，可以自定义实现命名Bean，
28 * 1、@ComponentScan(value = "spring.annotation.componentscan",nameGenerator = MyBeanNameGenerator.class)
29 * MyBeanNameGenerator.class 需要实现 BeanNameGenerator 接口，所有实现BeanNameGenerator 接口的实现类都会被调用
30 * 2、使用 AnnotationConfigApplicationContext 的 setBeanNameGenerator方法注入一个BeanNameGenerator
31 * BeanNameGenerator beanNameGenerator = (definition,registry)-> String.valueOf(new Random().nextInt(1000));
32 * AnnotationConfigApplicationContext annotationConfigApplicationContext = new AnnotationConfigApplicationContext();
33 * annotationConfigApplicationContext.setBeanNameGenerator(beanNameGenerator);
34 * annotationConfigApplicationContext.register(MainConfig2.class);
35 * annotationConfigApplicationContext.refresh();
36 * 第一种方式只会重命名@ComponentScan扫描到的注解类
37 * 第二种只有是初始化的注解类就会被重命名
38 * 列如第一种方式不会重命名 @Configuration 注解的bean名称，而第二种就会重命名 @Configuration 注解的Bean名称
39 */
40 Class<? extends BeanNameGenerator> nameGenerator() default BeanNameGenerator.class;
41
42 /**
43 * 用于解析@Scope注解，可通过 AnnotationConfigApplicationContext 的 setScopeMetadataResolver 方法重新设定处理类
44 * ScopeMetadataResolver scopeMetadataResolver = definition -> new ScopeMetadata(); 这里只是new了一个对象作为演示，没有做实际的逻辑操作
45 * AnnotationConfigApplicationContext annotationConfigApplicationContext = new AnnotationConfigApplicationContext();
46 * annotationConfigApplicationContext.setScopeMetadataResolver(scopeMetadataResolver);
47
48 * annotationConfigApplicationContext.register(MainConfig2.class);
49 * annotationConfigApplicationContext.refresh();
50 * 也可以通过@ComponentScan 的 scopeResolver 属性设置
51 *@ComponentScan(value = "spring.annotation.componentscan",scopeResolver = MyAnnotationScopeMetadataResolver.class)
52 */
53 Class<? extends ScopeMetadataResolver> scopeResolver() default AnnotationScopeMetadataResolver.class;
54
55 /**
56 * 用来设置类的代理模式
57 */
58 ScopedProxyMode scopedProxy() default ScopedProxyMode.DEFAULT;
59
60 /**
61 * 扫描路径 如 resourcePattern = "**/*.class"
62 * 使用 includeFilters 和 excludeFilters 会更灵活
63 */
64 String resourcePattern() default ClassPathScanningCandidateComponentProvider.DEFAULT_RESOURCE_PATTERN;
65
66 /**
67 * 指示是否应启用对带有{@code @Component}，{@ code @Repository}，
68 * {@ code @Service}或{@code @Controller}注释的类的自动检测。
69 */
70 boolean useDefaultFilters() default true;
71
72 /**
73 * 对被扫描的包或类进行过滤，若符合条件，不论组件上是否有注解，Bean对象都将被创建
74 * @ComponentScan(value = "spring.annotation.componentscan",includeFilters = {
75 * @ComponentScan.Filter(type = FilterType.ANNOTATION, classes = {Controller.class, Service.class}),
76 * @ComponentScan.Filter(type = FilterType.ASSIGNABLE_TYPE, classes = {SchoolDao.class}),
77 * @ComponentScan.Filter(type = FilterType.CUSTOM, classes = {MyTypeFilter.class}),
78 * @ComponentScan.Filter(type = FilterType.ASPECTJ, pattern = "spring.annotation..*"),
79 * @ComponentScan.Filter(type = FilterType.REGEX, pattern = "^[A-Za-z.]+Dao$")
80 * },useDefaultFilters = false)
81 * useDefaultFilters 必须设为 false
82 */
83 Filter[] includeFilters() default {};
84
85 /**
86 * 指定哪些类型不适合进行组件扫描。
87 * 用法同 includeFilters 一样
88 */
89 Filter[] excludeFilters() default {};
90
91 /**
92 * 指定是否应注册扫描的Bean以进行延迟初始化。
93 * @ComponentScan(value = "spring.annotation.componentscan",lazyInit = true)
94 */
95 boolean lazyInit() default false;
96
97
98 /**
99 * 用于 includeFilters 或 excludeFilters 的类型筛选器
100 */
101 @Retention(RetentionPolicy.RUNTIME)
102 @Target({})
103 @interface Filter {
104
105 /**
106 * 要使用的过滤器类型，默认为 ANNOTATION 注解类型
107 * @ComponentScan.Filter(type = FilterType.ANNOTATION, classes = {Controller.class, Service.class})
108 */
109 FilterType type() default FilterType.ANNOTATION;
110
111 /**
112 * 过滤器的参数，参数必须为class数组，单个参数可以不加大括号
113 * 只能用于 ANNOTATION 、ASSIGNABLE_TYPE 、CUSTOM 这三个类型
114 * @ComponentScan.Filter(type = FilterType.ANNOTATION, value = {Controller.class, Service.class})
115 * @ComponentScan.Filter(type = FilterType.ASSIGNABLE_TYPE, classes = {SchoolDao.class})
116 * @ComponentScan.Filter(type = FilterType.CUSTOM, classes = {MyTypeFilter.class})
117 */
118 @AliasFor("classes")
119 Class<?>[] value() default {};
120
121 /**
122 * 作用同上面的 value 相同
123 * ANNOTATION 参数为注解类，如 Controller.class, Service.class, Repository.class
124 * ASSIGNABLE_TYPE 参数为类，如 SchoolDao.class
125 * CUSTOM 参数为实现 TypeFilter 接口的类 ，如 MyTypeFilter.class
126 * MyTypeFilter 同时还能实现 EnvironmentAware，BeanFactoryAware，BeanClassLoaderAware，ResourceLoaderAware 这四个接口
127 * EnvironmentAware
128 * 此方法用来接收 Environment 数据 ，主要为程序的运行环境，Environment 接口继承自 PropertyResolver 接口，详细内容在下方
129 * @Override
130 * public void setEnvironment(Environment environment) {
131 * String property = environment.getProperty("os.name");
132 * }
133 *
134 * BeanFactoryAware
135 * BeanFactory Bean容器的根接口，用于操作容器，如获取bean的别名、类型、实例、是否单例的数据
136 * @Override
137 * public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
138 * Object bean = beanFactory.getBean("BeanName")
139 * }
140 *
141 * BeanClassLoaderAware
142 * ClassLoader 是类加载器，在此方法里只能获取资源和设置加载器状态
143 * @Override
144 * public void setBeanClassLoader(ClassLoader classLoader) {
145 * ClassLoader parent = classLoader.getParent();
146 * }
147 *
148 * ResourceLoaderAware
149 * ResourceLoader 用于获取类加载器和根据路径获取资源
150 * public void setResourceLoader(ResourceLoader resourceLoader) {
151 * ClassLoader classLoader = resourceLoader.getClassLoader();
152 * }
153 */
154 @AliasFor("value")
155 Class<?>[] classes() default {};
156
157 /**
158 * 这个参数是 classes 或 value 的替代参数，主要用于 ASPECTJ 类型和 REGEX 类型
159 * ASPECTJ 为 ASPECTJ 表达式
160 * @ComponentScan.Filter(type = FilterType.ASPECTJ, pattern = "spring.annotation..*")
161 * REGEX 参数为 正则表达式
162 * @ComponentScan.Filter(type = FilterType.REGEX, pattern = "^[A-Za-z.]+Dao$")
163 */
164 String[] pattern() default {};
165
166 }
167
168 }
Environment
1 public interface Environment extends PropertyResolver {
2
3 /**
4 * 这个方法用来取到 ConfigurableEnvironment.setActiveProfiles(String...) 设置的值，这个方法搭配 @Profile 注解使用
5 * 如 ：
6 * @Bean()
7 * @Profile("dev")
8 * public Student student() {
9 * System.out.println("createStudent");
10 * return new Student("王五", 18);
11 * }
12 *
13 * @Test
14 * public void testImport(){
15 * AnnotationConfigApplicationContext annotationConfigApplicationContext = new AnnotationConfigApplicationContext();
16 * ConfigurableEnvironment environment = annotationConfigApplicationContext.getEnvironment();
17 * environment.setActiveProfiles("dev");
18 * annotationConfigApplicationContext.register(MainConfig2.class);
19 * annotationConfigApplicationContext.refresh();
20 * String[] beanDefinitionNames = annotationConfigApplicationContext.getBeanDefinitionNames();
21 * for (String s : beanDefinitionNames) {
22 * System.out.println(s);
23 * }
24 * }
25 *
26 * @Profile("dev")
27 * environment.setActiveProfiles("dev");
28 * 当 setActiveProfiles 里的值在 @Profile 中存在，此时就会注册这个Bean
29 * 而 getActiveProfiles 取到的也是 setActiveProfiles 中的值
30 */
31 String[] getActiveProfiles();
32
33 /**
34 * 未明确设置有效配置文件时，返回默认有效的配置文件集
35 */
36 String[] getDefaultProfiles();
37
38 /**
39 * 返回一个或多个给定的配置文件是否处于活动状态，或者在没有显式活动
40 * 配置文件的情况下，返回一个或多个给定的配置文件是否包含在默认配置
41 * 文件集中。 如果个人资料以“！”开头 逻辑取反，即如果给定的配置文件未
42 * 激活，则该方法将返回true。 例如，如果配置文件“ p1”处于活动状态或“
43 * p2”处于非活动状态，则env.acceptsProfiles（“ p1”，“！p2”）将返回true。
44 * 不推荐使用
45 */
46 @Deprecated
47 boolean acceptsProfiles(String... profiles);
48
49 /**
50 * Return whether the {@linkplain #getActiveProfiles() active profiles}
51 * 返回活动概要文件是否 与给定Profiles谓词匹配。，不推荐使用
52 */
53 boolean acceptsProfiles(Profiles profiles);
54
55 }
PropertyResolver
1 public interface PropertyResolver {
2
3 /**
4 * 判断给定键的值是否为 null
5 */
6 boolean containsProperty(String key);
7
8 /**
9 * 返回给定键的值，如果不存在就返回 null
10 * @param key 键
11 */
12 @Nullable
13 String getProperty(String key);
14
15 /**
16 * 返回给定键的值，值若为 null 则返回默认值
17 * @param key 键
18 * @param defaultValue 指定返回的默认值
19 */
20 String getProperty(String key, String defaultValue);
21
22 /**
23 * 返回给定键的值，如果不存在就返回 null，需要指定返回的类型
24 * @param key 键
25 * @param targetType 指定返回的类型，不要用基础类型，用包装类
26 */
27 @Nullable
28 <T> T getProperty(String key, Class<T> targetType);
29
30 /**
31 * 返回给定键的值，如果不存在就返回默认值，需要指定返回的类型
32 * @param key 键
33 * @param targetType 指定的返回类型
34 * @param defaultValue 指定的返回默认值
35 *
36 */
37 <T> T getProperty(String key, Class<T> targetType, T defaultValue);
38
39 /**
40 * 返回给定键的值，如果不存在则抛出 IllegalStateException 异常
41 */
42 String getRequiredProperty(String key) throws IllegalStateException;
43
44 /**
45 * 返回给定键的值，如果不存在则抛出 IllegalStateException 异常，需要指定返回类型
46 * targetType 指定返回的类型
47 */
48 <T> T getRequiredProperty(String key, Class<T> targetType) throws IllegalStateException;
49
50 /**
51 * 在给定的文本中解析$ {...}占位符，将其替换为由 getProperty 解析的相应属性值。 没有默认值的无法解析的占位符将被忽略，并按原样传递。
52 * 比如 String str = environment.resolvePlaceholders("这是${os.name}系统");
53 * 返回值为 这是Windows 10系统
54 * @param text 需要被被解析的文本，若文本为 null 则会抛出IllegalStateException 异常
55 */
56 String resolvePlaceholders(String text);
57
58 /**
59 * 在给定的文本中解析$ {...}占位符，将其替换为 getProperty 解析的相应属性值。 没有默认值的无法解析的占位符将导致引发IllegalArgumentException。
60 * 比如 String s = environment.resolveRequiredPlaceholders("${}");
61 * 就会抛出 IllegalArgumentException异常
62 */
63 String resolveRequiredPlaceholders(String text) throws IllegalArgumentException;
64
65 }
ProPertyResolver.getProperty() 能获取的数据（->左边是键，右边是值）
PropertyResolver.getProperty 获取的数据有两类 systemProperties 和 systemEnvironment systemProperties 数据有（环境会有不同，数据会有区别） java.runtime.name -> Java(TM) SE Runtime Environment sun.boot.library.path -> D:\Program Files\Java\jdk1.8.0_171\jre\bin java.vm.version -> 25.171-b11 java.vm.vendor -> Oracle Corporation java.vendor.url -> http://java.oracle.com/ path.separator -> ; java.vm.name -> Java HotSpot(TM) 64-Bit Server VM file.encoding.pkg -> sun.io user.country -> CN user.script -> sun.java.launcher -> SUN_STANDARD sun.os.patch.level -> java.vm.specification.name -> Java Virtual Machine Specification user.dir -> D:\IDEAworkspaces\learn intellij.debug.agent -> true java.runtime.version -> 1.8.0_171-b11 java.awt.graphicsenv -> sun.awt.Win32GraphicsEnvironment java.endorsed.dirs -> D:\Program Files\Java\jdk1.8.0_171\jre\lib\endorsed os.arch -> amd64 java.io.tmpdir -> C:\Users\ADMINI~1\AppData\Local\Temp\ line.separator -> "\r\n" java.vm.specification.vendor -> Oracle Corporation user.variant -> os.name -> Windows 10 sun.jnu.encoding -> GBK java.library.path -> D:\Program Files\Java\jdk1.8.0_171\bin;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;D:\Program Files (x86)\NetSarang\Xshell 6\;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\iCLS\;C:\Program Files\Intel\Intel(R) Management Engine Components\iCLS\;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;D:\Program Files\MySQL\MySQL Server 5.5\bin;D:\Program Files\Java\jdk1.8.0_171\bin;D:\Program Files\apache-tomcat-8.5.33\bin;D:\Program Files\apache-maven-3.5.4\bin;D:\Program Files\TortoiseSVN\bin;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\Wirel jboss.modules.system.pkgs -> com.intellij.rt java.specification.name -> Java Platform API Specification java.class.version -> 52.0 sun.management.compiler -> HotSpot 64-Bit Tiered Compilers os.version -> 10.0 user.home -> C:\Users\Administrator user.timezone -> java.awt.printerjob -> sun.awt.windows.WPrinterJob file.encoding -> UTF-8 java.specification.version -> 1.8 java.class.path -> D:\Program Files\JetBrains\IntelliJ IDEA 2019.2.4\lib\idea_rt.jar;D:\Program Files\JetBrains\IntelliJ IDEA 2019.2.4\plugins\junit\lib\junit-rt.jar;D:\Program Files\JetBrains\IntelliJ IDEA 2019.2.4\plugins\junit\lib\junit5-rt.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\charsets.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\deploy.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\access-bridge-64.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\cldrdata.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\dnsns.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\jaccess.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\jfxrt.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\localedata.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\nashorn.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\sunec.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\sunjce_provider.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\sunmscapi.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\sunpkcs11.ja user.name -> Administrator java.vm.specification.version -> 1.8 sun.java.command -> com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 -junit4 IocTest,testImport java.home -> D:\Program Files\Java\jdk1.8.0_171\jre sun.arch.data.model -> 64 user.language -> zh java.specification.vendor -> Oracle Corporation awt.toolkit -> sun.awt.windows.WToolkit java.vm.info -> mixed mode java.version -> 1.8.0_171 java.ext.dirs -> D:\Program Files\Java\jdk1.8.0_171\jre\lib\ext;C:\WINDOWS\Sun\Java\lib\ext sun.boot.class.path -> D:\Program Files\Java\jdk1.8.0_171\jre\lib\resources.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\rt.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\sunrsasign.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\jsse.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\jce.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\charsets.jar;D:\Program Files\Java\jdk1.8.0_171\jre\lib\jfr.jar;D:\Program Files\Java\jdk1.8.0_171\jre\classes java.vendor -> Oracle Corporation file.separator -> \ java.vendor.url.bug -> http://bugreport.sun.com/bugreport/ idea.test.cyclic.buffer.size -> 1048576 sun.io.unicode.encoding -> UnicodeLittle sun.cpu.endian -> little sun.desktop -> windows sun.cpu.isalist -> amd64 systemEnvironment数据有 USERDOMAIN_ROAMINGPROFILE -> LAPTOP-FLP30M67 LOCALAPPDATA -> C:\Users\Administrator\AppData\Local PROCESSOR_LEVEL -> 6 IntelliJ IDEA -> D:\Program Files\JetBrains\IntelliJ IDEA 2019.2.4\bin; USERDOMAIN -> LAPTOP-FLP30M67 FPS_BROWSER_APP_PROFILE_STRING -> Internet Explorer LOGONSERVER -> \\LAPTOP-FLP30M67 JAVA_HOME -> D:\Program Files\Java\jdk1.8.0_171 SESSIONNAME -> Console ALLUSERSPROFILE -> C:\ProgramData PROCESSOR_ARCHITECTURE -> AMD64 TNS_ADMIN -> D:\Program Files\instantclient_18_3\network\admin PSModulePath -> C:\Program Files\WindowsPowerShell\Modules;C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules SystemDrive -> C: MAVEN_HOME -> D:\Program Files\apache-maven-3.5.4 OneDrive -> C:\Users\Administrator\OneDrive APPDATA -> C:\Users\Administrator\AppData\Roaming USERNAME -> Administrator ORACLE_HOME -> D:\Program Files\instantclient_18_3 ProgramFiles(x86) -> C:\Program Files (x86) CommonProgramFiles -> C:\Program Files\Common Files Path -> D:\Program Files (x86)\NetSarang\Xshell 6\;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\iCLS\;C:\Program Files\Intel\Intel(R) Management Engine Components\iCLS\;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;D:\Program Files\MySQL\MySQL Server 5.5\bin;D:\Program Files\Java\jdk1.8.0_171\bin;D:\Program Files\apache-tomcat-8.5.33\bin;D:\Program Files\apache-maven-3.5.4\bin;D:\Program Files\TortoiseSVN\bin;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\WirelessCommon\;D:\Program Files\nodejs\;C:\Program Files\NVIDIA Corporation\NVIDIA NvDLISR;d:\Prog FPS_BROWSER_USER_PROFILE_STRING -> Default PATHEXT -> .COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC DriverData -> C:\Windows\System32\Drivers\DriverData OS -> Windows_NT COMPUTERNAME -> LAPTOP-FLP30M67 PROCESSOR_REVISION -> 8e0a CommonProgramW6432 -> C:\Program Files\Common Files NLS_LANG -> AMERICAN_AMERICA.UTF8 ComSpec -> C:\WINDOWS\system32\cmd.exe ProgramData -> C:\ProgramData ProgramW6432 -> C:\Program Files HOMEPATH -> \Users\Administrator SystemRoot -> C:\WINDOWS TEMP -> C:\Users\ADMINI~1\AppData\Local\Temp HOMEDRIVE -> C: PROCESSOR_IDENTIFIER -> Intel64 Family 6 Model 142 Stepping 10, GenuineIntel USERPROFILE -> C:\Users\Administrator TMP -> C:\Users\ADMINI~1\AppData\Local\Temp CommonProgramFiles(x86) -> C:\Program Files (x86)\Common Files ProgramFiles -> C:\Program Files PUBLIC -> C:\Users\Public NUMBER_OF_PROCESSORS -> 8 windir -> C:\WINDOWS =:: -> ::\ IDEA_INITIAL_DIRECTORY -> C:\Users\Administrator\Desktop
标签：Files,jdk1.8,Java,ComponentScan,Program,171,class,详解 来源： https://www.cnblogs.com/chengmi/p/12073945.html