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该问题已被官方收录

@query的用法

0

1

Spring-data-jpa

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

该问题已被官方收录

tomcat安装配置好之后打不开

2

1

linux命令

class="cursor-pointer"> 详细描述

该问题已被官方收录

OSS图片无法上传

0

1

图片上传

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

class="cursor-pointer"> 源码

工具类：
package com.tools;

import com.aliyun.oss.OSSClient;
import org.apache.log4j.Logger;
import org.springframework.web.multipart.commons.CommonsMultipartFile;

import java.io.IOException;
import java.io.InputStream;

public class UploadFile {
    private static Logger logger=Logger.getLogger(UploadFile.class);
    public static  void  upFile(CommonsMultipartFile file,String objectName){
        logger.info("com.Tools.UploadFile.upFile的入参是 file"+file+" \n objectName"+objectName);
        // Endpoint以杭州为例，其它Region请按实际情况填写。
        String endpoint = "http://oss-cn-hangzhou.aliyuncs.com";
        // 云账号AccessKey有所有API访问权限，建议遵循阿里云安全最佳实践，创建并使用RAM子账号进行API访问或日常运维，请登录 https://ram.console.aliyun.com 创建。
        String accessKeyId = "xxx";
        String accessKeySecret = "xxx";
        // 创建OSSClient实例。
        OSSClient ossClient = new OSSClient(endpoint, accessKeyId, accessKeySecret);
        // 上传文件流。
        InputStream inputStream = null;
        try {
            inputStream =file.getInputStream();
        } catch (IOException e) {
            e.printStackTrace();
        }
        ossClient.putObject("arnold-cheng",objectName, inputStream);
        // 关闭OSSClient。
        ossClient.shutdown();
    }
}

form表单上传图片：
<form enctype="multipart/form-data" method="post" action=${pageContext.request.contextPath}"/uploadFile">
    <input type="file" name="uploadFile"/>
    <input type="submit" value="上传">
</form>

该问题已被官方收录

三层架构中使用策略模式，会使得三层架构中使用DAO层出现异常

1

第三方API调用

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

class="cursor-pointer"> 源码

controller
	// 执行上传图片到阿里云
	@RequestMapping(value = "/uploadToAliYun", method = RequestMethod.POST)
	@ResponseBody
	public void userPhotoUploadToALiYun(@RequestParam("file") MultipartFile file, HttpServletRequest request,
										HttpServletResponse response) throws IOException {

		String result = null;
		// 使用策略模式
		UserPhotoUploadStrategyContext context = new UserPhotoUploadStrategyContext(new UserPhotoUploadToAliYunOSSImpl());
		context.executeUserPhotoUploadStrategy(request,response,file);

		// 上传文件
		// result = userPhotoUploadToAliYunOSS.userPhotoUploadToOSS(request, response, file);
		PrintWriter out = response.getWriter();
		out.print(result);
		out.flush();
		out.close();
		logger.info("上传阿里云返回结果：" + result );

	}


services:
public interface UserPhotoUploadStrategy {


	String userPhotoUploadToOSS(HttpServletRequest request, HttpServletResponse response,
								MultipartFile file) throws IOException;

}


实现类：

	/**
	 *
	 * @param request 请求信息
	 * @param response 响应信息
	 * @param file 文件输入流
	 * @return key 存在于OSS 的键值
	 * @throws IOException IO流异常
	 */
	@Override
	public String userPhotoUploadToOSS(HttpServletRequest request, HttpServletResponse response,
									   MultipartFile file) throws IOException {

		applicationContext.getBean("oSSUtilsByALiYun");

		String key = "";
		String result ="";

				// 获取上传前源文件名、文件大小
		String originalFileName = file.getOriginalFilename();
		Long originalFileSize  = file.getSize();
		logger.info("上传前的文件名：" + originalFileName);

		// 将 multipartfilein 转化为 inputstream流
		CommonsMultipartFile cFile = (CommonsMultipartFile) file;
		DiskFileItem fileItem = (DiskFileItem) cFile.getFileItem();
		InputStream inputStream = fileItem.getInputStream();

		if (!file.isEmpty()){
			OSSClient ossClient = task07.util.aliyun.oss.OSSUtilsByALiYun.getOSSClient();
			String newFileName = null;
			if (originalFileName.length()>0){
				newFileName = UUID.randomUUID() +"";
			}
			// 将文件上传并获得返回值 key(文件名称)
			key = OSSUtilsByALiYun.uploadObject2OSS(ossClient, inputStream,
					OSSUtilsByALiYun.getBucketName(), originalFileName,newFileName,
					originalFileSize,OSSUtilsByALiYun.getFolder());

		}
		//将文件名写入数据库
		if (!key.equals("")){
			HttpSession userNamesession =request.getSession();
			String userName = (String) userNamesession.getAttribute("userName");

			if (userName.equals(null)){
				logger.info("写入数据库出错，用户名为 null");

			}

			logger.info("userName:" + userName );
			logger.info("key:" + key );

			System.out.println(userLoginDao);
			System.out.println(userLoginDao.queryByName(userName).toString());
			userLoginDao.updateHeadPhoto(userName,key);

			UserLogin userLoginText = userLoginDao.queryByName(userName);
			String databaseHeadPho =  userLoginText.getHead_photo();
			logger.info("写入数据库的key 值为： " + databaseHeadPho);
			// 将 key 值写入数据库


			if (databaseHeadPho.equals(key)){
				logger.info("写入文件一致，上传成功！");
				result = "文件上传成功!";
			}else{
				result = "上传成功，写入数据库不一致!";
			}


		}else {
			logger.info("文件上传失败！");
			result = "文件上传失败!";
		}

		return result;
	}
}
 
策略模式的context :
public class UserPhotoUploadStrategyContext {


	private UserPhotoUploadStrategy userPhotoUploadStrategy;


	public UserPhotoUploadStrategyContext( UserPhotoUploadStrategy userPhotoUploadStrategy){
		this.userPhotoUploadStrategy = userPhotoUploadStrategy;
	}

	public String executeUserPhotoUploadStrategy(HttpServletRequest request, HttpServletResponse response,
												 MultipartFile file) throws IOException {
		System.out.println("context 之前");

		return userPhotoUploadStrategy.userPhotoUploadToOSS(request, response, file);
	}

}

该问题已被官方收录

springboot怎么一直返回字符串呢？

0

1

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

该问题已被官方收录

maven打包的war项目，tomcat和jetty部署没有问题，resin报错

0

1

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

该问题已被官方收录

rmi客服端远程调用方法、对象报错ClassNoFound

1

分布式

class="cursor-pointer"> 详细描述

该问题已被官方收录

测试一下不关闭连接池的时候，在Main函数里写1000个循环调用会出现什么情况。

0

1

JDBC

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

该问题已被官方收录

使用腾讯云上传文件的时候，上传报错

1

第三方API调用

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

class="cursor-pointer"> 源码

        List<String> imgList = qiniuUtils.getFileList();
        for (int i = 0; i <imgList.size() ; i++) {
            String key1 = imgList.get(i);
            String url2 = qiniuUtils.getLink()+key1;
            URL urls = new URL(url2);
            InputStream inputStream = urls.openStream();
            ObjectMetadata meta = new ObjectMetadata();
            meta.setContentLength(inputStream.available());
            qcloudcos.UploadStream(key1,inputStream,meta);
        }

    public static String UploadStream(String key, InputStream input, ObjectMetadata metadata){
        COSClient cosClient = init();
        String bucketname ="test-"+APPID;
        try {
            PutObjectRequest putObjectRequest = new PutObjectRequest(bucketname,key,input,metadata);
            PutObjectResult objectResult = cosClient.putObject(putObjectRequest);
            cosClient.shutdown();
            return "success";
        }catch (Exception e){
            e.printStackTrace();
            cosClient.shutdown();
            return null;
        }
    }

该问题已被官方收录

spring读取不了properties文件

1

spring

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 源码

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
      http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <context:property-placeholder location="classpath:properties/memcache.properties"/>
    <bean id="memcachedClientBuilder" class="net.rubyeye.xmemcached.XMemcachedClientBuilder">
        <constructor-arg>
            <list>
                <bean class="java.net.InetSocketAddress">
                    <constructor-arg>

                        <value>${server1.host}</value>
                    </constructor-arg>
                    <constructor-arg>
                        <value>${server1.port}</value>
                    </constructor-arg>
                </bean>
            </list>
        </constructor-arg>
        <constructor-arg>
            <list>
                <value>${server1.weight}</value>
            </list>
        </constructor-arg>
        <property name="commandFactory">
            <bean class="net.rubyeye.xmemcached.command.TextCommandFactory"/>
        </property>
        <property name="sessionLocator">
            <bean class="net.rubyeye.xmemcached.impl.KetamaMemcachedSessionLocator"/>
        </property>
        <property name="transcoder">
            <bean class="net.rubyeye.xmemcached.transcoders.SerializingTranscoder"/>
        </property>
    </bean>

    <bean id="memcachedClient" factory-bean="memcachedClientBuilder"
          factory-method="build" destroy-method="shutdown"/>

    <bean id="memcachedUtil" class="jnshu.util.Memcached"/>

</beans>

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/aop
       http://www.springframework.org/schema/aop/spring-aop.xsd
       http://www.springframework.org/schema/tx
       http://www.springframework.org/schema/tx/spring-tx.xsd">

<context:annotation-config/>

<context:component-scan base-package ="jnshu">
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>

<context:property-placeholder location = "classpath:properties/mysql.properties"/>
    
    
    <bean id = "dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
        <property name="initialPoolSize" value="10"/>
        <property name="maxPoolSize" value="30"/>
        <property name="minPoolSize" value="10"/>
        <property name="autoCommitOnClose" value="false"/>
        <property name="checkoutTimeout" value="10000"/>
        <property name="acquireRetryAttempts" value="2"/>
    </bean>

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="mapperLocations" value="classpath:mapper/StudentDao.xml"/>
        <property name="typeAliasesPackage" value="jnshu.pojo"/>
        <property name="plugins">
            <array>
                <bean class="com.github.pagehelper.PageInterceptor">
                    <property name="properties">
                        <value>
                            reasonable=true
                        </value>
                    </property>
                </bean>
            </array>
        </property>
    </bean>
    
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="jnshu.dao"/>
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
    </bean>
    
    <bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate" scope="prototype">
        <constructor-arg name = "sqlSessionFactory" ref="sqlSessionFactory"/>
        <constructor-arg name="executorType" value="BATCH"/>
    </bean>
    
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>

<aop:config>
        
        <aop:pointcut id="servicePoint" expression="execution(* jnshu.service..*(..))"/>
        
        <aop:advisor advice-ref="txAdvice" pointcut-ref="servicePoint"/>
        
        <aop:aspect id="LogAop" ref="logAop">
            <aop:around method="LogAround" pointcut-ref="servicePoint"/>
        </aop:aspect>
    </aop:config>

<tx:advice id="txAdvice">
        <tx:attributes>
            
            <tx:method name="*"/>
            
            <tx:method name="get*" read-only = "true"/>
        </tx:attributes>
    </tx:advice>

</beans>

java.lang.IllegalStateException: Failed to load ApplicationContext

	at org.springframework.test.context.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:94)
	at org.springframework.test.context.DefaultTestContext.getApplicationContext(DefaultTestContext.java:72)
	at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:117)
	at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83)
	at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:212)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:200)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:252)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:254)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:217)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:83)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
	at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
	at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:68)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:163)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: org.springframework.beans.factory.BeanDefinitionStoreException: Invalid bean definition with name 'dataSource' defined in class path resource [spring/spring-dao.xml]: Could not resolve placeholder 'jdbc.driver' in string value "${jdbc.driver}"; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'jdbc.driver' in string value "${jdbc.driver}"
	at org.springframework.beans.factory.config.PlaceholderConfigurerSupport.doProcessProperties(PlaceholderConfigurerSupport.java:211)
	at org.springframework.context.support.PropertySourcesPlaceholderConfigurer.processProperties(PropertySourcesPlaceholderConfigurer.java:180)
	at org.springframework.context.support.PropertySourcesPlaceholderConfigurer.postProcessBeanFactory(PropertySourcesPlaceholderConfigurer.java:155)
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:265)
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:162)
	at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:606)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:462)
	at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:125)
	at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:60)
	at org.springframework.test.context.support.AbstractDelegatingSmartContextLoader.delegateLoading(AbstractDelegatingSmartContextLoader.java:109)
	at org.springframework.test.context.support.AbstractDelegatingSmartContextLoader.loadContext(AbstractDelegatingSmartContextLoader.java:261)
	at org.springframework.test.context.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:68)
	at org.springframework.test.context.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:86)
	... 24 more
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'jdbc.driver' in string value "${jdbc.driver}"
	at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:174)
	at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:126)
	at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:204)
	at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:178)
	at org.springframework.context.support.PropertySourcesPlaceholderConfigurer$2.resolveStringValue(PropertySourcesPlaceholderConfigurer.java:175)
	at org.springframework.beans.factory.config.BeanDefinitionVisitor.resolveStringValue(BeanDefinitionVisitor.java:282)
	at org.springframework.beans.factory.config.BeanDefinitionVisitor.resolveValue(BeanDefinitionVisitor.java:204)
	at org.springframework.beans.factory.config.BeanDefinitionVisitor.visitPropertyValues(BeanDefinitionVisitor.java:141)
	at org.springframework.beans.factory.config.BeanDefinitionVisitor.visitBeanDefinition(BeanDefinitionVisitor.java:82)
	at org.springframework.beans.factory.config.PlaceholderConfigurerSupport.doProcessProperties(PlaceholderConfigurerSupport.java:208)
	... 36 more