老师，跑测试的时候报错：Method com/mchange/v2/c3p0/impl/NewProxyPreparedStatement.isClosed()Z is abstract c3p由<groupId>c3p0</groupId>artifactId>c3p0</artifactId>
<version>0.9.1.2</version>换成oupId>com.mchange</groupId>
<artifactId>c3p0</artifactId><version>0.9.5.2</version>也不对
同学好，这得和你的Spring版本严格对应起来，否则isClosed这个方法没有被实现，也就是c3p0版本不相符，你可以看看你的maven dependencies里的jar有没有重复的c3p0.
下面是我的pom
<?xml version="1.0" encoding="UTF-8"?><project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.imooc</groupId> <artifactId>o2o</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>war</packaging> <name>o2o</name> <description>Demo project for Spring Boot</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.8.RELEASE</version> <relativePath /> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <dependencies> <!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-classic --> <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-classic</artifactId> </dependency> <!-- Servlet web --> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> </dependency> <!-- json解析 --> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> </dependency> <!-- Map工具类 对标准java Collection的扩展 spring-core.jar需commons-collections.jar --> <dependency> <groupId>commons-collections</groupId> <artifactId>commons-collections</artifactId> </dependency> <!-- 数据库 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <!-- 图片处理 --> <!-- https://mvnrepository.com/artifact/net.coobird/thumbnailator --> <dependency> <groupId>net.coobird</groupId> <artifactId>thumbnailator</artifactId> <version>0.4.8</version> </dependency> <!-- https://mvnrepository.com/artifact/com.github.penggle/kaptcha --> <dependency> <groupId>com.github.penggle</groupId> <artifactId>kaptcha</artifactId> <version>2.3.2</version> </dependency> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.2</version> </dependency> <!-- redis客户端:Jedis --> <dependency> <groupId>redis.clients</groupId> <artifactId>jedis</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.1</version> </dependency> <!-- 二维码相关 --> <!-- https://mvnrepository.com/artifact/com.google.zxing/javase --> <dependency> <groupId>com.google.zxing</groupId> <artifactId>javase</artifactId> <version>3.3.0</version> </dependency> <!-- https://mvnrepository.com/artifact/org.quartz-scheduler/quartz --> <dependency> <groupId>org.quartz-scheduler</groupId> <artifactId>quartz</artifactId> <version>2.3.0</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson --> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.45</version> </dependency> <!-- https://mvnrepository.com/artifact/com.squareup.okhttp3/okhttp --> <dependency> <groupId>com.squareup.okhttp3</groupId> <artifactId>okhttp</artifactId> <version>3.9.1</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build></project>
我昨天也是这个问题，我一顿乱整，已解决。pom：
<dependencies><dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.1</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <dependency> <groupId>com.mchange</groupId> <artifactId>c3p0</artifactId> <version>0.9.2.1</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>com.mchange</groupId> <artifactId>mchange-commons-java</artifactId> <version>0.2.3.4</version> </dependency> </dependencies>
我解决了。在pom.xml中加入jar包，c3p0需要。。。 <dependency> <groupId>com.mchange</groupId> <artifactId>mchange-commons-java</artifactId> <version>0.2.3.4</version> </dependency>
一样解决了告诉我一下。。