{"id":1948,"date":"2019-01-04T08:38:46","date_gmt":"2019-01-04T00:38:46","guid":{"rendered":"http:\/\/ufqi.com\/blog\/?p=1948"},"modified":"2019-01-04T08:39:57","modified_gmt":"2019-01-04T00:39:57","slug":"tomcat-jdbc-mysql-namingcontext","status":"publish","type":"post","link":"https:\/\/ufqi.com\/blog\/tomcat-jdbc-mysql-namingcontext\/","title":{"rendered":"Apache Tomcat JDBC\u8fde\u63a5\u6c60\u63a5\u5165MySQL\u6570\u636e\u5e93\u7684NamingContext\u5f02\u5e38\u6392\u89e3"},"content":{"rendered":"

\u5728\u6700\u8fd1\u65b0\u90e8\u7f72\u7684 -GWA2<\/a> in Java \u7684\u5b9e\u4f8b\u4e2d\uff0c\u4e00\u5207\u8fdb\u5c55\u987a\u5229\uff0c\u552f\u72ec\u5728\u542f\u7528\u8fde\u63a5\u6c60\u8bbf\u95ee Tomcat \u63a5\u7ba1\u7684 MySQL \u6570\u636e\u5e93\u8fde\u63a5\u6c60\u65f6\u62a5\u9519\u51fa\u5f02\u5e38\u3002\u95ee\u9898\u6392\u89e3\u8fc7\u7a0b\u66f2\u6298\uff0c\u503c\u5f97\u8bb0\u5f55\u5982\u4e0b\u3002\u670d\u52a1\u5668\u7aef\u65e5\u5fd7\u4fe1\u606f\u5982\u4e0b\uff1a<\/p>\n

\n

java.lang.ClassCastException: class org.apache.naming.NamingContext cannot be cast to class javax.sql.DataSource (org.apache.naming.NamingContext is in unnamed module of loader java.net.URLClassLoader @5383967b; javax.sql.DataSource is in module java.sql of loader ‘platform’)<\/p>\n<\/blockquote>\n

\u6839\u636e\u62a5\u9519\u4fe1\u606f\uff0c\u627e\u51fa\u62a5\u51fa\u95ee\u9898\u7684\u4ee3\u7801\u6bb5\u5982\u4e0b\uff1a<\/p>\n

\n

if(this.hasSocketPool){
try{
\u00a0 \u00a0 this.ctx = new InitialContext();
\u00a0 \u00a0 this.ds = (DataSource)ctx.lookup(“java:comp\/env\/jdbc\/”+this.myDb); \/\/- error!
}
catch(Exception ex){
ex.printStackTrace();
}
}<\/p>\n<\/blockquote>\n

\u5c31\u662f\u5728 ctx.lookup \u8fd4\u56de\u5bf9\u8c61\u8fdb\u884c\u5f3a\u5236\u7c7b\u578b\uff08DataSource\uff09\u8f6c\u6362\u65f6\u53d1\u9001\u9519\u8bef\uff0c\u629b\u51fa\u5f02\u5e38\u3002<\/p>\n

\u8ba9\u4eba\u8d39\u89e3\u7684\u662f\uff0c\u8fd9\u4e9b\u4ee3\u7801\u5728\u53e6\u5916\u7684\u8fd0\u884c\u65f6\u73af\u5883\u65f6\uff0c\u8fd0\u884c\u826f\u597d\uff0c\u96be\u9053\u8ddf\u65b0\u90e8\u7f72\u7684\u73af\u5883\u6709\u5173\uff1f Tomcat 9.0+ \/ MySql 8.0+ \/ Java 11.0+ ?<\/p>\n

\u62a5\u9519\u4fe1\u606f\u7684\u5b57\u9762\u610f\u601d\u662f \u201cA\u7c7b\u4e0d\u80fd\u5f3a\u5236\u8f6c\u4e3aB\u7c7b\uff08A\u7c7b\u5728\u672a\u547d\u540d\u7684\u52a0\u8f7d\u5668\u6a21\u5757C\u4e2d\uff0cB\u7c7b\u5728platform\u52a0\u8f7d\u5668\u7684java.sql\u6a21\u5757\u4e2d\uff09\u201d\u3002\u6839\u636e\u8fd9\u4e9b\u7406\u89e3\uff0c\u5927\u81f4\u662f\u52a0\u8f7d\u7684\u7c7b\u51fa\u73b0\u9519\u4e71\u4e86\uff0c\u4e8e\u662f\u6cbf\u7740\u8fd9\u4e2a\u601d\u8def\u641c\u7d22\u4e00\u4e0b\u7f51\u4e0a\u5176\u4ed6\u540c\u5b66\u7684\u8fc7\u5f80\u7ecf\u5386\u3002<\/p>\n

\u7f51\u4e0a\u7684\u8d44\u8baf\u5927\u81f4\u53ef\u4ee5\u5206\u4e3a\u4e24\u79cd\uff0c\u4e00\u79cd\u662f\u7684\u786e\u52a0\u8f7d\u9519\u4e86\u00a0org.apache.naming.* \u76f8\u5173\u7684\u7c7b\uff0c\u53e6\u5916\u4e00\u79cd\u66f4\u5927\u7684\u53ef\u80fd\u662f\u6ca1\u6709\u6b63\u786e\u5730\u5728 Tomcat\u4e2d\u914d\u7f6e conf\/server.xml \u548c conf\/web.xml \uff0c\u8fd9\u4e2a\u53c2\u7167 Tomcat\u7684\u624b\u518c\u53ef\u4ee5\u5f88\u5feb\u6392\u9664\u3002<\/p>\n

\u800c\u7b2c\u4e00\u79cd\uff0c\u52a0\u8f7d\u9519\u4e71\u7684\u60c5\u51b5\uff0c\u5728GWA2 Java\u4e2d\uff0c\u7406\u8bba\u4e0a\u4e0d\u5e94\u8be5\u53d1\u751f\uff0c\u56e0\u4e3a\u6211\u4eec\u5728 inc\/MySql.class \u4e2d\u660e\u786e\u5730\u58f0\u660e\u4e86\u52a0\u8f7d\u5982\u4e0b\u7c7b:<\/p>\n

\n

<%@page import=”javax.sql.DataSource,
java.sql.DriverManager,
java.sql.ResultSet,
java.sql.PreparedStatement,
javax.naming.Context,
javax.naming.InitialContext”%><\/p>\n<\/blockquote>\n

\u663e\u7136\uff0c\u5176\u4e2d\u5e76\u6ca1\u6709\u663e\u793a\u5730\u52a0\u8f7d\u4efb\u4f55 org.apache.naming \u76f8\u5173\u7684\u7c7b\u3002\u5c3d\u7ba1\u5982\u6b64\uff0c\u6211\u4eec\u8fd8\u662f\u5728\u4ee3\u7801\u5c42\u9762\u5c06\u7c7b\u7684\u8c03\u7528\u518d\u4e00\u6b21\u7684\u660e\u786e\u4e0b\u6765\uff0c\u4f7f\u7528\u7c7b\u7684\u7edd\u5bf9\u8def\u5f84\u4ee5\u907f\u514d\u53ef\u80fd\u5f15\u8d77\u7684\u6df7\u6dc6\u3002\u6539\u8fdb\u540e\u7684\u4ee3\u7801\u4e3a\uff1a<\/p>\n

\n

javax.naming.Context ctx = new javax.naming.InitialContext();
javax.naming.Context envCtx = (javax.naming.Context)ctx.lookup(“java:comp\/env”);
envCtx = (javax.naming.Context)envCtx;
Object dsObj = envCtx.lookup(“jdbc\/”+this.myDb);<\/p>\n<\/blockquote>\n

\u5f88\u9057\u61be\uff0c\u5e26\u4e0a\u7edd\u5bf9\u8def\u5f84\u7684\u7c7b\u7684\u58f0\u660e\u4e0e\u5e94\u7528\u4e8e\u4e8b\u65e0\u8865\u3002<\/p>\n

\u8feb\u4e0d\u5f97\u5df2\uff0c\u6211\u4eec\u51b3\u5b9a\u5c06\u90e8\u7f72\u5f52\u96f6\uff0c\u6e05\u7a7a\u6240\u6709\u914d\u7f6e\uff0c\u91cd\u65b0\u4e0b\u8f7d\u6700\u65b0\u7248\u7684 Tomcat, GWA2 Java\u7b49\uff0c\u7136\u540e\u91cd\u65b0\u5b89\u88c5\uff0c\u518d\u6b21\u8fd0\u884c\u65f6\uff0c\u5f88\u9057\u61be\uff0c\u95ee\u9898\u4f9d\u65e7\uff01<\/p>\n

\u51e0\u4e4e\u8981\u653e\u5f03\u4e86\uff0c\u8fd9\u79cd\u53ef\u80fd\u7531\u4e8e\u8f6f\u4ef6\u4e0d\u5339\u914d\u5bfc\u81f4\u7684\u95ee\u9898\uff0c\u5df2\u7ecf\u8d85\u51fa\u5e94\u7528\u5c42\u548c\u4ee3\u7801\u5c42\u7684\u89e3\u51b3\u80fd\u529b\u8303\u7574\u3002\u4e0d\u80fd\u653e\u5f03\uff0c\u8fd8\u6709\u6700\u540e\u4e00\u62db\u2014\u2014\u5206\u6790\u6e90\u4ee3\u7801\u2014\u2014\u8fd8\u6ca1\u4f7f\u7528\u3002\u4e8e\u662f\u8010\u4e0b\u5fc3\u6765\uff0c\u7ffb\u770b Tomcat \u7684API\u6587\u6863\u548c Java \u7684API \u6587\u6863\uff0c\u9010\u4e2a\u5bf9\u8c61\u67e5\u8be2\u3001\u5206\u6790\uff0c\u5e76\u5728\u7a0b\u5e8f\u4e2d\u9010\u4e2a\u6b65\u9aa4\u8fdb\u884c\u65ad\u70b9\u6d4b\u8bd5\u3002<\/p>\n

\n

javax.naming.NamingEnumeration dsList = envCtx.list(“jdbc\/”);
debug(“dsObj:”+dsObj+” \/ “+dsObj.toString()+” ctx:”+ctx+” envctx:”+envCtx+” envctx.getEnv:”+envCtx.getEnvironment());
debug(“dsList:”+dsList+” mydb:”+this.myDb);
while(dsList.hasMore()){
\u00a0 \u00a0 debug(“dsList: next:”+dsList.next());
}<\/p>\n<\/blockquote>\n

-R\/B2SR<\/a>\u00a0<\/b>
https:\/\/tomcat.apache.org\/tomcat-9.0-doc\/api\/index.html<\/p>\n

-R\/72SS<\/a>\u00a0<\/b>
https:\/\/docs.oracle.com\/en\/java\/javase\/11\/docs\/api\/java.naming\/javax\/naming\/Context.html<\/p>\n

\u8fdb\u4e00\u6b65\u5730\u65e5\u5fd7\u8f93\u51fa\u4e2d\uff0c\u6211\u4eec\u770b\u5230\u4e86\u86db\u4e1d\u9a6c\u8ff9\uff0c\u5728\u6d4b\u8bd5\u4ee3\u7801\u7684\u7b2c\u4e8c\u6b65\uff0c\u539f\u672c\u5e94\u8be5\u8fd4\u56de javax.naming.Context \u5bf9\u8c61\u7684\uff0c\u5374\u88ab Tomcat \u66ff\u6362\u4e3a org.apache.naming.NamingContext. \u6240\u4ee5\u540e\u5c31\u51e0\u4e4e\u5168\u90fd\u8dd1\u504f\u4e86\u3002<\/p>\n

\n

Thu Jan 03 05:56:32 UTC 2019 dsObj:org.apache.naming.NamingContext@368631b7 \/ org.apache.naming.NamingContext@368631b7 ctx:javax.naming.InitialContext@4f52e2fc envctx:org.apache.naming.NamingContext@5b51d294 envctx.getEnv:{}
Thu Jan 03 05:56:32 UTC 2019 dsList:org.apache.naming.NamingContextEnumeration@152fa16f mydb:
Thu Jan 03 05:56:32 UTC 2019 dsList: next:userdb: org.apache.tomcat.dbcp.dbcp2.BasicDataSource
Thu Jan 03 05:56:32 UTC 2019 dsList: next:contentdb: org.apache.tomcat.dbcp.dbcp2.BasicDataSource
Thu Jan 03 05:56:32 UTC 2019 dsList: next:newsdb: org.apache.tomcat.dbcp.dbcp2.BasicDataSource<\/p>\n<\/blockquote>\n

\u5f53\u6211\u4eec\u8c03\u7528\u00a0org.apache.naming.NamingContext \u5bf9\u8c61\u7684\u65b9\u6cd5 .getEnvironment \u548c .list \u8fdb\u4e00\u6b65\u5730\u8f93\u51fa\u65f6\u53d1\u73b0\uff0c\u914d\u7f6e\u4fe1\u606f userdb, contentdb \u548c newsdb \u90fd\u5728\u3002 \u4e3a\u4f55\u8fd4\u56de\u662f\u4e00\u4e2a\u5305\u542b\u5217\u8868\u7684\u5bf9\u8c61NamingContext \u800c\u4e0d\u662f\u4e00\u4e2a DataSource\u7c7b\u578b\u7684\u6570\u636e\uff1f<\/p>\n

\u8c1c\u5e95\u63ed\u5f00\uff01\u5728\u5f53\u524d\u8fd0\u884c\u65f6\u73af\u5883\u4e2d\u5173\u952e\u53d8\u91cf this.myDb \u4e3a\u7a7a\uff0c\u5f53\u4f20\u5165\u4e00\u4e2a\u7a7a\u503c\u7684 \u8d44\u6e90\u6807\u8bc6\u7b26\uff08\u6570\u636e\u5e93\u8d44\u6e90\uff09\u65f6\uff0cctx.lookup \u4e0d\u662f\u62a5\u9519\u672a\u627e\u5230\uff0c\u800c\u662f\u8fd4\u56de\u4e86DataSource\u7684\u7236\u7c7b NamingContext\uff01<\/p>\n

\n

(DataSource)ctx.lookup(“java:comp\/env\/jdbc\/”+this.myDb); \/\/- error if empty myDb<\/p>\n<\/blockquote>\n

\u4fee\u6b63\u65b9\u5f0f\uff1a
1\uff09\u5728 GWA2 Java\u4e2d\u5bf9 this.myDb \u505a\u517c\u5bb9\uff0c\u5982\u679c\u4e3a\u7a7a\uff0c\u5219\u4e0d\u542f\u7528\u9ed8\u8ba4\u6570\u636e\u5e93\u8fde\u63a5\u6c60\u7684\u8fde\u63a5\uff1b
2\uff09\u5c1d\u8bd5\u9012\u4ea4 bug\u7ed9 Apache Tomcat \u5f00\u53d1\u7ec4\uff0c\u4fee\u6539\u62a5\u9519\u4fe1\u606f\u6216\u6539\u8fdb\u8fd4\u56de\u503c\u7c7b\u578b\uff0c\u51cf\u5c11\u5bf9\u7528\u6237\u53ef\u80fd\u4ea7\u751f\u8bef\u5bfc\u7684\u4fe1\u606f\u3002
3) \u5c1d\u8bd5\u56de\u590dstackoverflow\u4e0a\u7c7b\u4f3c\u60ac\u800c\u672a\u51b3\u7684\u4e00\u95ee\u9898\u3002<\/p>\n

\u7ffb\u9605\u6e90\u4ee3\u7801\uff0c\u4ed4\u7ec6\u67e5\u770bAPI\u6587\u6863\u4f9d\u7136\u662f\u89e3\u51b3\u95ee\u9898\u7684\u7ec8\u6781\u5927\u6740\u5668\u4e4b\u4e00\u3002<\/strong><\/p>\n

<\/p>\n

-GWA2 \u662f\u201d\u901a\u7528\u7f51\u7edc\u5e94\u7528\u67b6\u6784( General Web Application Architeture )\u201d\uff0c\u57fa\u4e8e -GWA2 \u53ef\u4ee5\u8f7b\u4fbf\u6784\u5efa\u5404\u79cd\u7f51\u7edc\u5e94\u7528\u7a0b\u5e8f,
\u5305\u62ec\u590d\u6742\u7684\u5728\u7ebf\u8d2d\u7269\u5546\u57ce\u3001\u00a0\u65c5\u6e38\u4ea4\u6613\u5e73\u53f0\u3001\u793e\u7fa4\u6216\u8005\u793e\u4ea4\u7f51\u7ad9\u548c\u65b0\u95fb\u8d44\u8baf\u7f51\u7ad9\u7b49\uff0c
\u4e5f\u5305\u62ec\u5404\u79cd\u4f01\u4e8b\u4e1a\u5355\u4f4d\u7f51\u4e0a\u95e8\u6237\uff0c\u5728\u7ebf\u4ea4\u4e92\u53ca\u670d\u52a1\u4f5c\u4e1a\u7cfb\u7edf\u7b49.
\u8fd8\u53ef\u4ee5\u5305\u62ec\u4e3aNativeApp\u505a\u670d\u52a1\u5668\u7aef\u652f\u6301, \u751a\u81f3\u662fWebApp\u7684\u5168\u90e8.
-GWA2 \u662f\u4e3a\u6570\u4e0d\u591a\u7684\u652f\u6301\u8de8\u5f00\u53d1\u8bed\u8a00\u7684\u5e94\u7528\u6846\u67b6\uff0c\u76ee\u524d\u652f\u6301 -Java, -PHP, -Perl, -Aspx and -Python .<\/p>\n

-GWA2 is a \u201cGeneral Web Application Architecture\u201d and based on -GWA2 developers can easily build a variety of network applications,
including complex online shopping malls, travel trading platforms, community or social networking sites and news information sites, etc.
Also the applications include various online portals of enterprises and institutions, online interaction and service operations systems.
Moreover it contains server-side support for NativeApp, or even all of the WebApp.
-GWA2 is one of the web frameworks which provide cross-language support for -Java, -PHP, -Perl, -Aspx and -Python at present.<\/p>\n

-GWA2 is E.A.S.Y\u00a0<\/strong>
Easy Along, Swift Yield
<\/b>\u8f7b\u677e\u542f\u52a8, \u5feb\u901f\u4ea7\u51fa.<\/p>\n","protected":false},"excerpt":{"rendered":"

\u5728\u6700\u8fd1\u65b0\u90e8\u7f72\u7684 -GWA2 in Java \u7684\u5b9e\u4f8b\u4e2d\uff0c\u4e00\u5207\u8fdb\u5c55\u987a\u5229\uff0c\u552f\u72ec\u5728\u542f\u7528\u8fde … \u7ee7\u7eed\u9605\u8bfb →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[42,6,2],"tags":[86,146,255,229,271],"_links":{"self":[{"href":"https:\/\/ufqi.com\/blog\/wp-json\/wp\/v2\/posts\/1948"}],"collection":[{"href":"https:\/\/ufqi.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ufqi.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ufqi.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ufqi.com\/blog\/wp-json\/wp\/v2\/comments?post=1948"}],"version-history":[{"count":7,"href":"https:\/\/ufqi.com\/blog\/wp-json\/wp\/v2\/posts\/1948\/revisions"}],"predecessor-version":[{"id":1955,"href":"https:\/\/ufqi.com\/blog\/wp-json\/wp\/v2\/posts\/1948\/revisions\/1955"}],"wp:attachment":[{"href":"https:\/\/ufqi.com\/blog\/wp-json\/wp\/v2\/media?parent=1948"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ufqi.com\/blog\/wp-json\/wp\/v2\/categories?post=1948"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ufqi.com\/blog\/wp-json\/wp\/v2\/tags?post=1948"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}