Some pits of Object to Map

Here, three methods of Object mapping are summarized 1. Use reflection getDeclaredFields and getFields /** * Clean the data of the incoming object, remove the null and '' property values, and store the other field names and property values in the map collection */ public Map<String,Object> objectToMap(Object requestParame ...

Posted on Tue, 03 Dec 2019 00:12:25 -0500 by jackofalltrades

springboot learning notes

(VI) springboot integrates activemq 1. Now download ActiveMQ. Download link: http://activemq.apache.org/download.html. After the windows system is decompressed, enter the bin directory. It is divided into 32-bit and 64 bit operating systems. Run the activemq.bat startup program. Visit http://http://127.0.0.1:8161   The interface appears to indi ...

Posted on Mon, 02 Dec 2019 10:28:26 -0500 by shamly

Saltstack user guide 03 configuration management

1. Host planning Matters needing attention If the configuration file of master or minion is modified, the corresponding service must be restarted. 2. Understand YAML Specific address https://docs.saltstack.com/en/latest/topics/yaml/index.html YAML: three board axe 1. Indent: 2 spaces, cannot use Tab 2. Colon: key: value note that there are ...

Posted on Mon, 02 Dec 2019 10:06:33 -0500 by geowulf

mybatis automatically fills in the time field

For the created ﹣ on and updated ﹣ on entities, it is unnecessary for developers to intervene, because it is enough to explain the use scenario, that is, when inserting and updating data, record the current time. For mybatis, it can be realized through interceptors. Remember that the methods implemented in jpa are mainly realized through jpa ...

Posted on Mon, 02 Dec 2019 03:07:49 -0500 by karenruth

How does Mybatis work

Objectives: Clarify the process of mybatis loading and parsing mapper file; Clarify the process of executing SQL by mybatis. When analyzing the source code of mybatis loading configuration, the previous article mentioned org.apache.ibatis.builder.xml.xmlconfigbuilder ා parseconfiguration method, and now continues to analyze mapperElement meth ...

Posted on Sun, 01 Dec 2019 23:30:46 -0500 by eon201

Implementation of database operation read-write separation based on Spring and Mybatis interceptor

First, configure the master-slave synchronization of the database: The last article wrote: https://www.cnblogs.com/xuyiqing/p/10647133.html   Why should we separate reading from writing? In general, most of the read operations of Web applications are much more than the write operations In order to improve efficiency, we can consider the se ...

Posted on Sun, 01 Dec 2019 20:09:31 -0500 by ajsuk

Initialization of JVM class loader class

core-java.jpg For a static field, only the class that defines the field directly can be initialized. When a class is initializing, all its parent classes must be initialized. class MParent{ public static final String mString = "hello jvm"; static { System.out.println("call MParent static block"); } } pub ...

Posted on Sun, 01 Dec 2019 18:34:14 -0500 by johnbrayn

Perfect compilation and installation of Apache2.4.38+apr-1.6.5+apr-util.1.61

First of all, the environment is ready for installation [root@minion-1 ~]#yum install -y libxml2-devel pcre-devel openssl-devel expat-devel && yum -y groupinstall "Development Tools" apche compilation requires two components: APR and APR util. If the link fails because of the latest package, click this website directory to find o ...

Posted on Sun, 01 Dec 2019 17:48:50 -0500 by Cereals

[SpringBoot integration] 1. Integrating kafka

brief introduction About kafka. Before you install the kafka service again. Reference documents: spring for kafka documentation spring boot for kafka document 1. Dependency package <!-- kafka --> <dependency> <groupId>org.springframework.kafka</groupId> <artifactId>spring-kafka</art ...

Posted on Sun, 01 Dec 2019 08:52:59 -0500 by adrian28uk

hadoop learning and compiling source code

Custom Catalog title is written here 1. Preparatory work 2.jar package installation 3. Compile source code 1. Preparatory work CentOS CentOS can connect to the Internet, Linux virtual machine ping www.baidu.com It is smooth.Note: compile with root role to reduce the problem of folder permission jar package preparatio ...

Posted on Sun, 01 Dec 2019 01:09:48 -0500 by sgiandhu