Java

Jetty is too smart. If there is any JVM option provided, Jetty will spawn a new JVM instance to do the real work, even if you don’t use “–exec” option in start.ini And jetty’s logback module introduces a JVM option. See here You will see: -Dorg.eclipse.jetty.util.log.class?=org.eclipse.jetty.util.log.Slf4jLog So does it matter? It matters a lot because …

Jetty’s start.jar forks a new JVM to run the app if logback module is enabled Read More »

compile ‘io.springfox:springfox-swagger2:2.9.2’ compile ‘io.springfox:springfox-swagger-ui:2.9.2’ /** See https://www.baeldung.com/swagger-2-documentation-for-spring-rest-api */ @Configuration @EnableSwagger2 public class SwaggerConfig { @Value(“${enable.swagger}”) //You may want to disabled it in PROD boolean enableSwagger; @Bean public Docket api() { Docket api = new Docket(DocumentationType.SWAGGER_2) .select() .apis(RequestHandlerSelectors.basePackage(“your.package”)) .paths(PathSelectors.any()) .build(); ApiInfo apiInfo = new ApiInfoBuilder() .version(“xxx”) .description(“xxx”) .termsOfServiceUrl(“xxx”) .title(“Xxx Doc”) .build(); api.useDefaultResponseMessages(false).apiInfo(apiInfo); api.enable(enableSwagger); return api; } …

Code snippet: Swagger + Spring Boot Read More »

You can use OpenPDF to draw a PDF (the open source fork of iText). However, the learning curve of creating PDF with layouts and stuff is very high. A more cost-effective solution is create an HTML version of it and convert it using Flying Saucer with its OpenPDF component . As a Java developer you …

Generate PDF from server side using Java Read More »

/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * “License”); you may not use this …

Read process output in Java without hanging the main thread Read More »

Do this: apply plugin: ‘maven-publish’ publishing { publications { maven( MavenPublication ) { artifact theTaskThatGeneratesJar } } repositories { maven { def releasesRepoUrl = http://…/repositories/releases/’ def snapshotsRepoUrl = ‘http://…/repositories/snapshots/’ url = version.endsWith(‘SNAPSHOT’) ? snapshotsRepoUrl : releasesRepoUrl credentials { username ‘xxx’ password ‘xxx’ } } } }

Instead, run it with: java -jar start.jar “bin/jetty.sh start” does a lot of doggy things for you. You will get suprising results if you use it, for example, the logs inside your war are not shown. Avoid it unless you do know about those things

If the images are external image links that can be accessed by http url, then nothing speical needs to be done. If the images are external image files, then you have 2 choices. Embed the images as base64 strings. . This is simple. However email clients such as gmail will refuse to render them Using …

Sending html emails with images inside Read More »

Before you start Get a domain If you haven’t got one, you can buy one. You can get it from AWS Route 53 Get a SSL certificate for your domain You can get it from AWS Certificate Manager. Create an IAM User You will need this user’s access key and access secret to run eb-cli …

Things to do for a serious Java website when using Elastic Beanstalk Read More »

When I use “model” for the attribute name in the Jsp views, it only works in the original view, but not in other parts of the whole, merged view. But when I use “it” instead, everything works. I don’t know why. Maybe Jersey removes “model” from request attributes after rendering the original view

<!– pom.xml –> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>1.7.7</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.7.7</version> </dependency> <!– src/main/resources/log4j.xml –> <?xml version=”1.0″ encoding=”UTF-8″?> <!DOCTYPE log4j:configuration SYSTEM “log4j.dtd”> <log4j:configuration xmlns:log4j=”http://jakarta.apache.org/log4j/”> <appender name=”my-file-appender” class=”org.apache.log4j.FileAppender”> <param name=”file” value=”some.file” /> <param name=”append” value=”true” /> <param name=”encoding” value=”UTF-8″ /> <layout class=”org.apache.log4j.PatternLayout”> <param name=”ConversionPattern” value=”%d %t %-5p %c – %m%n” /> </layout> </appender> <appender name=”console” …

Quick log4j set up Read More »