{"id":127,"date":"2021-04-16T00:24:28","date_gmt":"2021-04-15T16:24:28","guid":{"rendered":"https:\/\/explause.com\/?p=127"},"modified":"2022-07-02T23:00:24","modified_gmt":"2022-07-02T15:00:24","slug":"spring-bean%e7%9a%84%e5%b1%9e%e6%80%a7%e4%bb%a5%e5%8f%8a%e8%ae%be%e7%bd%ae","status":"publish","type":"post","link":"https:\/\/devdoge.org\/?p=127","title":{"rendered":"\u5173\u4e8eBean"},"content":{"rendered":"\n

Bean\u5c31\u662fJava\u91cc\u9762\u7684\u5bf9\u8c61\u7684\u5b9e\u4f8b\uff0c\u6240\u4ee5\uff0cclass\u6587\u4ef6\u4ec5\u4ec5\u662f\u5bf9\u8c61\u7684\u5b9a\u4e49\u3002
\u6240\u4ee5\u624d\u9700\u8981\u6309\u7167\u5b9a\u4e49\u521b\u5efa\uff08new\uff09\u4e00\u4e2a\u5b9e\u4f8b\u3002<\/p>\n\n\n\n

\u5c5e\u6027<\/strong><\/p>\n\n\n\n

class<\/strong><\/td>\u5b9a\u4e49bean\u7684\u7c7b\uff0c\u5fc5\u987b\u8981\u6709<\/td><\/tr>
id<\/strong><\/td>bean\u7684\u540d\u5b57<\/td><\/tr>
scope<\/strong><\/td>bean\u4f5c\u7528\u57df<\/td><\/tr>
constructor-arg<\/strong><\/td>\u6784\u9020\u5668\u4f9d\u8d56\u6ce8\u5165\u7528\u5230\u7684\u53c2\u6570<\/td><\/tr>
property<\/strong><\/td>\u4f9d\u8d56\u6ce8\u5165\u7684\u53c2\u6570<\/td><\/tr>
autowire<\/strong><\/td>\u81ea\u52a8\u88c5\u914d\u6a21\u5f0f<\/td><\/tr>
lazy-initialization<\/strong><\/td>bean\u7b2c\u4e00\u6b21\u88ab\u8bf7\u6c42\u65f6\u518d\u521d\u59cb\u5316<\/td><\/tr>
init-method<\/strong><\/td>bean\u521d\u59cb\u5316\u540e\u6267\u884c\u7684\u65b9\u6cd5<\/td><\/tr>
destroy-method<\/strong><\/td>bean\u9500\u6bc1\u540e\u6267\u884c\u7684\u65b9\u6cd5<\/td><\/tr>
abstract<\/strong><\/td>\u4f5c\u4e3a\u6a21\u7248\u4f7f\u7528\uff0c\u548cclass\u51b2\u7a81<\/td><\/tr>
parent<\/strong><\/td>\u6307\u5b9a\u7236bean<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

\u4f5c\u7528\u57df<\/strong><\/p>\n\n\n\n

Bean\u5bf9\u8c61\u5728\u5bb9\u5668\u5185\u751f\u6548\u7684\u8303\u56f4\uff0c\u662f\u6574\u4e2a\u5bb9\u5668\u8fd8\u662f\u5355\u4e2a\u5b9e\u4f8b\u3002<\/p>\n\n\n\n

singleton<\/strong><\/td>\u5728\u4e00\u4e2a\u5bb9\u5668\u5185\u53ea\u6709\u4e00\u4e2a\u5b9e\u4f8b\uff08\u9ed8\u8ba4\uff09<\/td><\/tr>
prototype<\/strong><\/td>\u6bcf\u6b21\u8bf7\u6c42\u8fd9\u4e2aBean\u90fd\u65b0\u521b\u5efa\u4e00\u4e2a<\/td><\/tr>
request<\/strong><\/td>Bean\u5b58\u5728\u4e8eHTTP\u8bf7\u6c42<\/td><\/tr>
session<\/strong><\/td>Bean\u5b58\u5728\u4e8eHTTP\u4f1a\u8bdd<\/td><\/tr>
global-session<\/strong><\/td>Bean\u5b58\u5728\u4e8e\u5168\u5c40HTTP\u4f1a\u8bdd<\/td><\/tr><\/tbody><\/table>
request<\/strong>\u548csession<\/strong>\u548cglobal-session<\/strong>\u4ec5\u5728WEB\u5e94\u7528\u91cc\u751f\u6548\uff01<\/figcaption><\/figure>\n\n\n\n

\u4f8b\u5b50\uff1a\uff08\u5148\u6309\u7167\u8fd9\u91cc<\/a>\u521b\u5efa\u4e00\u4e2a\u9879\u76ee\uff0c\u6216\u8005\u4e0b\u8f7d\u6211\u505a\u597d\u7684<\/a>\uff09
\u5728src\/main\/resources\u6587\u4ef6\u5939\u4e0b\u521b\u5efaBeans.xml\u6587\u4ef6:<\/strong><\/p>\n\n\n\n

<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<beans xmlns = \"http:\/\/www.springframework.org\/schema\/beans\"\n   xmlns:xsi = \"http:\/\/www.w3.org\/2001\/XMLSchema-instance\"\n   xsi:schemaLocation = \"http:\/\/www.springframework.org\/schema\/beans\n   http:\/\/www.springframework.org\/schema\/beans\/spring-beans-3.0.xsd\">\n\n\t<bean id='helloWorld' class='com.explause.SpringExamples.HelloWorld' scope='prototype'\/>\n<\/beans><\/code><\/pre>\n\n\n\n
\u7136\u540e\u521b\u5efaHelloWorld.java\u6587\u4ef6<\/strong>:<\/strong><\/p>\n\n\n\n
package com.explause.SpringExamples;\n\npublic class HelloWorld {\n\tprivate String message;\n\t\n\tpublic void setMessage(String message){\n\t\tthis.message  = message;\n\t}\n\tpublic void getMessage(){\n\t\tSystem.out.println(\"Your Message : \" + message);\n\t}\n}<\/code><\/pre>\n\n\n\n
\u6700\u540e\u7684main\u51fd\u6570\u5165\u53e3BeanConfigDemo.java\u6587\u4ef6<\/strong>\uff1a<\/p>\n\n\n\n
package com.explause.SpringExamples;\n\nimport org.springframework.context.support.ClassPathXmlApplicationContext;\n\npublic class BeanConfigDemo {\n\tpublic static void main(String[] args) {\n\t\tClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(\"Beans.xml\");\n\t\tHelloWorld obj1 = (HelloWorld) context.getBean(\"helloWorld\");\n\t\tobj1.setMessage(\"Hello World\");\n\t\tobj1.getMessage();\n\t\t\n\t\tHelloWorld obj2 = (HelloWorld) context.getBean(\"helloWorld\");\n\t\tobj2.getMessage();\n\t\tcontext.close();\n\t}\n}<\/code><\/pre>\n\n\n\n
\u6700\u7ec8\u7684\u9879\u76ee\u7ed3\u6784\uff1a<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\u6267\u884cmain\u51fd\u6570\uff08\u65b9\u6cd5\uff09\u540e\u7684\u7ed3\u679c\uff1a<\/p>\n\n\n\n
\"\"
\u7531\u4e8e\u662f\u5728Spring Boot\u9879\u76ee\u4e0b\u8fd0\u884c\u7684\uff0c\u6240\u4ee5\u4f1a\u6709\u4e00\u4e9b\u9644\u52a0\u7684debug\u4fe1\u606f\u3002<\/figcaption><\/figure>\n\n\n\n
\u56e0\u4e3a\u5728singleton\u4f5c\u7528\u57df\u4e0b\uff0c\u4e00\u4e2a\u5bb9\u5668\u5185\u8fd9\u4e2a\u7c7b\u578b\u7684\u5bf9\u8c61\u53ea\u6709\u4e00\u4e2a\u5b9e\u4f8b\uff0c\u600e\u4e48\u8fd4\u56de\u90fd\u662f\u8fd4\u56de\u540c\u4e00\u4e2a\u5bf9\u8c61\u3002<\/p>\n\n\n\n
\u5982\u679c\u5c06\u4f5c\u7528\u57df\u6539\u6210singleton\uff0c\u90a3\u4e48\u8f93\u51fa\u7684\u4e24\u6761\u6d88\u606f\u90fd\u662f\u4e00\u6837\u7684\uff0c\u5373Hello World\u3002<\/strong><\/a><\/p>\n\n\n\n
\u751f\u547d\u5468\u671f\u7ba1\u7406<\/strong><\/p>\n\n\n\n
Bean\u5b9e\u4f8b\u5316\u4e4b\u540e\u53ef\u80fd\u9700\u8981\u505a\u4e00\u4e9b\u521d\u59cb\u5316\u5de5\u4f5c\uff0cBean\u4ece\u5bb9\u5668\u91cc\u79fb\u9664\u4e4b\u540e\u4e5f\u9700\u8981\u4e00\u4e9b\u6e05\u7406\u5de5\u4f5c,
\u6709\u4e24\u79cd\u65b9\u6cd5\uff0c\u4e00\u79cd\u662f\u5728xml\u6587\u4ef6\u91cc\u914d\u7f6e\uff0c\u4e00\u79cd\u662f\u5b9e\u73b0\u4e24\u4e2a\u63a5\u53e3\u3002<\/p>\n\n\n\n
xml\u6587\u4ef6\u91cc\u9762\u5b9a\u4e49\u7684\u8bdd\u5c31\u8981\u5728Bean\u7684\u6e90\u7801\u6587\u4ef6\u91cc\u5199\u597d\u51fd\u6570\uff08\u65b9\u6cd5\uff09\uff0c\u7136\u540e\u5728xml\u6587\u4ef6\u91cc\u914d\u7f6e
bean\u6807\u7b7e\u7684init-method\u6216destroy-method\u5c5e\u6027\u3002
\u5b9e\u73b0\u63a5\u53e3\u6709InitializingBean\u548cDisposableBean\u4e24\u4e2a\u3002<\/p>\n\n\n\n
\u4f8b\u5b50\uff1a<\/p>\n\n\n\n
BeansLifeCycle.xml\u6587\u4ef6:<\/strong><\/p>\n\n\n\n
<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<beans xmlns = \"http:\/\/www.springframework.org\/schema\/beans\"\n   xmlns:xsi = \"http:\/\/www.w3.org\/2001\/XMLSchema-instance\"\n   xsi:schemaLocation = \"http:\/\/www.springframework.org\/schema\/beans\n   http:\/\/www.springframework.org\/schema\/beans\/spring-beans-3.0.xsd\">\n\n\t<bean id='helloWorld' class='com.explause.SpringExamples.HelloWorldLifeCycle' scope='singleton' init-method='init' destroy-method='end'>\n\t\t<property name=\"message\" value='Hello World'\/>\n\t<\/bean>\n<\/beans><\/code><\/pre>\n\n\n\n
HelloWorldLifeCycle.java\u6587\u4ef6:<\/strong><\/p>\n\n\n\n
package com.explause.SpringExamples;\n\nimport org.springframework.beans.factory.DisposableBean;\nimport org.springframework.beans.factory.InitializingBean;\n\npublic class HelloWorldLifeCycle implements InitializingBean, DisposableBean {\n\tprivate String message;\n\t\n\tpublic void setMessage(String message){\n\t\tthis.message  = message;\n\t}\n\t\n\tpublic void getMessage(){\n\t\tSystem.out.println(\"Your Message : \" + message);\n\t}\n\t\n\tpublic void init() {\n\t\tSystem.out.println(\"In the init method.\");\n\t}\n\t\n\tpublic void end() {\n\t\tSystem.out.println(\"In the end method.\");\n\t}\n\n\t@Override\n\tpublic void destroy() throws Exception {\n\t\tSystem.out.println(\"In the destroy method.\");\n\t}\n\n\t@Override\n\tpublic void afterPropertiesSet() throws Exception {\n\t\tSystem.out.println(\"In the afterPropertiesSet method.\");\n\t}\n\n}<\/code><\/pre>\n\n\n\n
BeanLifeCycleDemo.java\u6587\u4ef6:<\/strong><\/p>\n\n\n\n
package com.explause.SpringExamples;\n\nimport org.springframework.context.support.ClassPathXmlApplicationContext;\n\npublic class BeanLifeCycleDemo {\n\tpublic static void main(String[] args) {\n\t\tClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(\"BeansLifeCycle.xml\");\n\t\tHelloWorldLifeCycle obj1 = (HelloWorldLifeCycle) context.getBean(\"helloWorld\");\n\t\tobj1.getMessage();\n\t\tcontext.close();\n\t}\n}<\/code><\/pre>\n\n\n\n
\"\"
\u9700\u8981\u6ce8\u610f\u7684\u662f\u63a5\u53e3\u7684\u4f18\u5148\u7ea7\u9ad8\u4e8eBeans.xml\u6587\u4ef6\u3002<\/strong><\/figcaption><\/figure>\n\n\n\n
\u540e\u671f\u5904\u7406<\/strong><\/p>\n\n\n\n
\u901a\u8fc7BeanPostProcessor<\/strong>\u63a5\u53e3\uff0c\u53ef\u4ee5\u653e\u4e00\u4e9b\u81ea\u5b9a\u4e49\u903b\u8f91\uff0c\u4f9d\u8d56\u89e3\u6790\u7b49\u884c\u4e3a\u3002\u4e5f\u53ef\u4ee5\u642d\u914dOrdered\u63a5\u53e3\u914d\u7f6e\u591a\u4e2a\u5b9e\u73b0\u3002\u4f5c\u4e3aBean\u914d\u7f6e\u5728xml\u6587\u4ef6\u91cc\u9762\u3002<\/p>\n\n\n\n
\u4f8b\u5b50\uff1a\u5728\u4e0a\u9762\u751f\u547d\u5468\u671f\u7ba1\u7406\u7684\u4f8b\u5b50<\/strong>\u91cc\u6dfb\u52a0\u4e00\u4e2aHelloWorldPostProcessor.java\u6587\u4ef6<\/strong>\uff1a<\/p>\n\n\n\n
package com.explause.SpringExamples;\n\nimport org.springframework.beans.BeansException;\nimport org.springframework.beans.factory.config.BeanPostProcessor;\n\npublic class HelloWorldPostProcessor implements BeanPostProcessor {\n\t@Override\n\tpublic Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {\n\t\tSystem.out.println(\"BeforeInitialization : \" + beanName);\n\t\treturn bean;\n\t}\n\t\n\t@Override\n\tpublic Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {\n\t\tSystem.out.println(\"AfterInitialization : \" + beanName);\n\t\treturn bean;\n\t}\n}<\/code><\/pre>\n\n\n\n
BeansLifeCycle.xml\u6587\u4ef6:<\/strong>
\u6dfb\u52a0\u4e86\u6ce8\u518cHelloWorldPostProcessor\u7684\u4ee3\u7801\uff1a<\/p>\n\n\n\n
<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<beans xmlns = \"http:\/\/www.springframework.org\/schema\/beans\"\n   xmlns:xsi = \"http:\/\/www.w3.org\/2001\/XMLSchema-instance\"\n   xsi:schemaLocation = \"http:\/\/www.springframework.org\/schema\/beans\n   http:\/\/www.springframework.org\/schema\/beans\/spring-beans-3.0.xsd\">\n\n\t<bean id='helloWorld' class='com.explause.SpringExamples.HelloWorldLifeCycle' scope='singleton' init-method='init' destroy-method='end'>\n\t\t<property name=\"message\" value='Hello World'\/>\n\t<\/bean>\n\t<bean class=\"com.explause.SpringExamples.HelloWorldPostProcessor\"\/>\n<\/beans><\/code><\/pre>\n\n\n\n
\"\"
\u53ef\u4ee5\u770b\u89c1BeanPostProcessor\u63a5\u53e3\u4f18\u5148\u7ea7\u6700\u9ad8\u3002<\/strong><\/figcaption><\/figure>\n\n\n\n
Bean\u5b9a\u4e49\u7ee7\u627f<\/strong><\/p>\n\n\n\n
\u5b50\u7c7b\u8bbe\u7f6eparent\u5c5e\u6027\uff0c\u7236\u7c7b\u7684\u540c\u540d\u5c5e\u6027\u4f1a\u88ab\u5b50\u7c7b\u8986\u76d6\uff0c\u5982\u679c\u6709\u7684\u8bdd\u3002 \u8fd8\u53ef\u4ee5\u8bbe\u7f6e\u6a21\u7248bean\uff0c\u6ca1\u6709class\u5c5e\u6027\u3002<\/strong><\/p>\n\n\n\n
\u4f8b\u5b50\uff1a
BeansParent.xml\u6587\u4ef6\uff1a<\/strong><\/p>\n\n\n\n
<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<beans xmlns = \"http:\/\/www.springframework.org\/schema\/beans\"\n   xmlns:xsi = \"http:\/\/www.w3.org\/2001\/XMLSchema-instance\"\n   xsi:schemaLocation = \"http:\/\/www.springframework.org\/schema\/beans\n   http:\/\/www.springframework.org\/schema\/beans\/spring-beans-3.0.xsd\">\n\n\t<bean id='helloWorld' class='com.explause.SpringExamples.HelloWorld'>\n\t\t<property name=\"message\" value='Hello World'\/>\n\t<\/bean>\n\t<bean id='helloWorld2' class='com.explause.SpringExamples.HelloWorld2' parent='helloWorld'>\n\t\t<property name=\"message2\" value='Hello World 2'\/>\n\t<\/bean>\n<\/beans><\/code><\/pre>\n\n\n\n
HelloWorld.java\u6587\u4ef6\uff1a<\/strong><\/p>\n\n\n\n
package com.explause.SpringExamples;\n\npublic class HelloWorld {\n\tprivate String message;\n\t\n\tpublic void setMessage(String message){\n\t\tthis.message  = message;\n\t}\n\tpublic void getMessage(){\n\t\tSystem.out.println(\"Your Message : \" + message);\n\t}\n}<\/code><\/pre>\n\n\n\n
HelloWorld2.java\u6587\u4ef6\uff1a<\/strong><\/p>\n\n\n\n
package com.explause.SpringExamples;\n\npublic class HelloWorld2 {\n\tprivate String message;\n\tprivate String message2;\n\t\n\tpublic void setMessage(String message){\n\t\tthis.message  = message;\n\t}\n\tpublic void getMessage(){\n\t\tSystem.out.println(\"Your Message : \" + message);\n\t\tSystem.out.println(\"Your Message 2 : \" + message2);\n\t}\n\tpublic void setMessage2(String message2){\n\t\tthis.message2  = message2;\n\t}\n}<\/code><\/pre>\n\n\n\n
BeanParentDemo.java\u6587\u4ef6\uff1a<\/strong><\/p>\n\n\n\n
package com.explause.SpringExamples;\n\nimport org.springframework.context.support.ClassPathXmlApplicationContext;\n\npublic class BeanParentDemo {\n\tpublic static void main(String[] args) {\n\t\tClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(\"BeansParent.xml\");\n\t\tHelloWorld obj1 = (HelloWorld) context.getBean(\"helloWorld\");\n\t\tobj1.getMessage();\n\t\t\n\t\tHelloWorld2 obj2 = (HelloWorld2) context.getBean(\"helloWorld2\");\n\t\tobj2.getMessage();\n\t\tcontext.close();\n\t}\n}<\/code><\/pre>\n\n\n\n
\"\"<\/figure>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
Spring\u6846\u67b6\u9488\u5bf9Bean\u7684\u4e00\u4e9b\u5c5e\u6027\u4ee5\u53ca\u8bbe\u7f6e\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[18],"class_list":["post-127","post","type-post","status-publish","format-standard","hentry","category-spring","tag-spring"],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":6}},"_links":{"self":[{"href":"https:\/\/devdoge.org\/index.php?rest_route=\/wp\/v2\/posts\/127","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devdoge.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devdoge.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devdoge.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/devdoge.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=127"}],"version-history":[{"count":31,"href":"https:\/\/devdoge.org\/index.php?rest_route=\/wp\/v2\/posts\/127\/revisions"}],"predecessor-version":[{"id":771,"href":"https:\/\/devdoge.org\/index.php?rest_route=\/wp\/v2\/posts\/127\/revisions\/771"}],"wp:attachment":[{"href":"https:\/\/devdoge.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=127"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devdoge.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=127"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devdoge.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=127"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}