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@jonikarppinen
jonikarppinen / StringUtils.java
Last active August 29, 2015 14:20
StringUtils – common utility methods for Java
/**
* @author Joni Karppinen
* Licence: WTFPL, http://www.wtfpl.net/txt/copying/
*/
public class StringUtils {
public static String encodeUrlParameters(Map<String, String> parameters) {
if (parameters == null || parameters.isEmpty()) {
return "";
}
@jonikarppinen
jonikarppinen / Specs2-output.txt
Last active December 8, 2015 20:34
Specs2 output when run in IntelliJ IDEA: "Test framework quit unexpectedly" (see http://stackoverflow.com/questions/34159857/specs2-how-to-test-a-class-with-more-than-one-injected-dependency)
Testing started at 22:28 ...
services.ReportServiceSpec$
java.lang.ClassNotFoundException: services.ReportServiceSpec$
STACKTRACE
java.net.URLClassLoader.findClass(URLClassLoader.java:381)
java.lang.ClassLoader.loadClass(ClassLoader.java:424)
sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
@jonikarppinen
jonikarppinen / Question20442265.java
Last active December 30, 2015 17:39
Answer for this question about Gson: http://stackoverflow.com/questions/20442265/how-to-decode-json-with-unknown-field-using-gson. This demonstrates how to use custom deserialiser to parse a big list of properties of the same type but unknown/random/varying names. Besides JDK, depends on Guava library.
import com.google.common.base.Charsets;
import com.google.common.io.Files;
import com.google.gson.*;
import java.io.File;
import java.io.IOException;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
@jonikarppinen
jonikarppinen / play-error-response.html
Last active September 30, 2016 16:08
HTML error response generated automatically by Play Framework (related to the question http://stackoverflow.com/q/39794500/56285)
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bad request</title>
<link rel="shortcut icon" href="data:image/png;base64,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
@jonikarppinen
jonikarppinen / proguard-project.txt
Last active August 1, 2017 09:56
Example ProGuard config for a project using RxJava, Guava and Gson
# Add project specific ProGuard rules here.
# By default, the flags in this file are appended to flags specified
# in ${sdk.dir}/tools/proguard/proguard-android.txt
# You can edit the include path and order by changing the ProGuard
# include property in project.properties.
#
# For more details, see
# http://developer.android.com/guide/developing/tools/proguard.html
@jonikarppinen
jonikarppinen / CustomObjectMapper.java
Last active June 28, 2018 21:28
Example of making Jackson behave more sensibly by default (also, more like Gson)
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
/**
* ObjectMapper customised for my tastes and most typical needs
*
* @author Joni Karppinen
*/
@jonikarppinen
jonikarppinen / ContactsFragment.java
Last active February 23, 2020 09:43
Fixes to "Retrieving a List of Contacts" Android tutorial by Google: https://developer.android.com/training/contacts-provider/retrieve-names.html
// Fixes to compilation errors in "Define the onItemClick() method" section
// Doesn't compile
Cursor cursor = parent.getAdapter().getCursor();
// Fixed (not sure if this is the cleanest way though)
Cursor cursor = ((SimpleCursorAdapter) parent.getAdapter()).getCursor();
// Doesn't compile
mContactId = getLong(CONTACT_ID_INDEX);
// Fixed
@jonikarppinen
jonikarppinen / Messages.java
Last active February 23, 2021 23:36
Example of using message resources in Spring Boot service layer code, in as simple way as possible (hopefully!). NOTE: this approach supports only a single locale, not dynamically changing it.
package com.company.project.components;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.MessageSource;
import org.springframework.context.support.MessageSourceAccessor;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
import java.util.Locale;
@jonikarppinen
jonikarppinen / CustomErrorController.java
Last active June 16, 2021 02:19
Example of replacing Spring Boot "whitelabel" error page with custom error responses (with JSON response body)
package com.company.project.controllers;
import com.company.project.model.api.ErrorJson;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.web.ErrorAttributes;
import org.springframework.boot.autoconfigure.web.ErrorController;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.context.request.RequestAttributes;
@jonikarppinen
jonikarppinen / PdfOrErrorController.java
Last active November 17, 2021 11:49
Example of using ExceptionHandler in Spring Boot: a controller method that returns either binary data or error JSON
package com.company.project.controllers;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import java.util.Random;