spring处理bean

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在这介绍一下spring的BeanPostProcessor类，它可以在初始化bean的前后做些必要的准备，比如一些数据库里的初始化数据等，例子如下（bootstrap.java）：

import javax.sql.DataSource;import org.hibernate.SessionFactory;import org.springframework.beans.BeansException;import org.springframework.beans.factory.config.BeanPostProcessor;import org.springframework.jdbc.core.JdbcTemplate;public class BootStrap implements BeanPostProcessor {private DataSource dataSource;/** * 执行脚本的路径 */private String sqlpath="存放sql语句的文件夹路径"; //初始化bean之后public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {if (bean instanceof DataSource){this.dataSource = (DataSource)bean;return bean;} else if (bean instanceof SessionFactory){//这时DDL已经完成Boot();return bean;} else return bean;} //初始化bean之前public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {return bean;}public void Boot() {JdbcTemplate jt = new JdbcTemplate(this.dataSource);//确定是否第一次启动程序int cnt = jt.queryForInt("select count(1) from users ");if (cnt!=0) {return;}SqlscriptExecutor sqlexec = new SqlscriptExecutor(dataSource);try {sqlexec.execute(sqlpath);} catch (Exception e) {}}}

SqlscriptExecutor类：

import java.io.InputStream;import java.io.InputStreamReader;import java.io.Reader;import java.util.ArrayList;import java.util.List;import javax.sql.DataSource;import org.apache.tools.ant.DirectoryScanner;import org.springframework.jdbc.core.JdbcTemplate;import org.springframework.util.FileCopyUtils;/** * 读取 SQL 脚本并执行 */public class SqlscriptExecutor {private DataSource dataSource;public SqlscriptExecutor(DataSource dataSource){this.dataSource = dataSource;}private String[] findFiles(String sqlpath){DirectoryScanner ds = new DirectoryScanner();ds.setIncludes(new String[]{sqlpath+"/*.sql"});String basedir = this.getClass().getResource("/").getPath();ds.setBasedir(basedir);ds.setCaseSensitive(true);ds.scan();String[] files = ds.getIncludedFiles();return files;}/** * 读取 SQL 文件，获取 SQL 语句 * @param sqlFile SQL 脚本文件 * @return List<sql> 返回所有 SQL 语句的 List * @throws Exception */private String[] loadSql(String sqlFile) throws Exception {List<String> sqlList = new ArrayList<String>();sqlFile = "/"+sqlFile.replace('//', '/');InputStream sqlFileIn = this.getClass().getResourceAsStream(sqlFile);Reader reader = new InputStreamReader(sqlFileIn,"UTF-8");String sqls = FileCopyUtils.copyToString(reader);String[] sqlArr = sqls.split("(;//s*//r//n)|(;//s*//n)");return sqlArr;} /** * 传入连接来执行 SQL 脚本文件 * @param conn 传入数据库连接 * @param sqlFile SQL 脚本文件 * @throws Exception */public void execute(String sqlpath) throws Exception {String[] sqlFiles = findFiles(sqlpath);JdbcTemplate jt = new JdbcTemplate(this.dataSource);for (String sqlFile:sqlFiles){String[] sqls = loadSql(sqlFile);for (String sql:sqls){ if (sql.endsWith(";")) sql = sql.substring(0,sql.length()-1); try{ jt.update(sql); }catch (Exception e){ }}}}public DataSource getDataSource() {return dataSource;}public void setDataSource(DataSource dataSource) {this.dataSource = dataSource;}}

在spring配置文件中加入：