I am trying to create a guice singleton from a json config file.
My singleton is the config:
#Singleton
public class QConfig {
private int port;
public int getPort() {
return port;
}
}
I use gson to generate the object:
String content = ...
QConfig config = new GsonBuilder().create().fromJson(content, QConfig.class);
Is there a way that I can generate the QConfig class myself and still use it a as a singleton
Use a #Provides method in a guice module :
#Provides
public QConfig config() {
String content = ...
QConfig config = new GsonBuilder().create().fromJson(content, QConfig.class);
}
Related
I went through the link: How to pass a Map<String, String> with application.properties and other related links multiple times, but still its not working.
I'm using Spring Boot and Spring REST example. Link Question: How to by default execute the latest version of endpoint in Spring Boot REST?.
I've created mapping something like this and simply read the mapping
get.customers={GET: '/app-data/customers', VERSION: 'v1'}
post.customers={POST: '/app-data/customers', VERSION: 'v1'}
get.customers.custId={GET: '/app-data/customers/{custId}', VERSION: 'v2'}
Code:
private String resolveLastVersion() {
// read from configuration or something
return "2";
}
Code:
#Component
#ConfigurationProperties
#PropertySource("classpath:restendpoint.properties")
public class PriorityProcessor {
private final Map<String, String> priorityMap = new HashMap<>();
public Map<String, String> getPriority() {
return priorityMap;
}
}
Code:
I suggest the following implementation:
#ConfigurationProperties(prefix="request")
public class ConfigurationProps {
private List<Mapping> mapping;
public List<Mapping> getMapping() {
return mapping;
}
public void setMapping(List<Mapping> mapping) {
this.mapping = mapping;
}
}
Class Mapping will denote the information about the single mapping:
public class Mapping {
private String method;
private String url;
private String version;
public Mapping(String method, String url, String version) {
this.method = method;
this.url = url;
this.version = version;
}
public Mapping() {
}
// getters setters here
}
On the Configuration or spring boot application class (the one with main method):
#EnableConfigurationProperties(ConfigurationProps.class)
In the properties file put:
request.mapping[0].method=get
request.mapping[0].url=/customers
request.mapping[0].version=1
request.mapping[1].method=post
request.mapping[1].url=/students
request.mapping[1].version=2
In Filter (I assume you followed my suggestion from the linked question):
#Component
#Order(1)
public class LatestVersionFilter implements Filter {
private List<Mapping> mappings;
public LatestVersionFilter(ConfigurationProps props) {
this.mappings = props.getMapping();
}
}
How can I use a variable as key for a Map in a yaml property file.
Example properties.yml :
aVariableAsKey: key
anOtherVariableAsValue: value
app:
my-map:
${aVariableAsKey} : ${anOtherVariableAsValue}
MyProperties class :
#ConfigurationProperties(prefix = "app", ignoreUnknownFields = false)
public class MyProperties {
private Map<String, String> myMap = new HashMap<>();
//getter and setter
}
Using this example result with the MyProperties class having { "aVariableAsKey": "value" } in "myMap".
Thanks
define new config class for example
#Configuration
#EnableConfigurationProperties
#ConfigurationProperties("my-map")
public class MyappConfig {
aVariableAsKey;
anOtherVariableAsValue; //you can assign aVariableAsKey to this variable
//getter and setter
}
///Add this code to assign aVariableAsKey inside of Yaml code
my-map:
aVariableAsKey : key
I have a class which is composed of 2 different objects :
public class MyClass{
private OptionClass optionClass;
private ConstantClass constantClass;
public DocumentToSignRestRequest(OptionClass optionClass, ConstantClass constantClass) {
this.optionClass= optionClass;
this.constantClass= constantClass;
}
}
My first class is a classic POJO. My second class retrieve values from the application.properties file.
public class ConstantClass {
#Value("${api.url}")
private String hostName;
#Value("${sign.path}")
private String pathStart;
public ConstantClass () {
this.hostName= getHostName();
this.path = getPath();
}
I map MyClass with MyClassDto in order to call a service.
#PostMapping(
value="/sign",
consumes = { MediaType.APPLICATION_XML_VALUE, MediaType.APPLICATION_JSON_VALUE },
produces = { MediaType.APPLICATION_XML_VALUE, MediaType.APPLICATION_JSON_VALUE }
)
public MyClassRest prepareDocument(#RequestBody DocumentToPrepare documentToPrepare) throws Exception {
MyClassRest returnValue = new MyClassRest ();
ModelMapper modelMapper = new ModelMapper();
MyClassDto myClassDto = modelMapper.map(documentToPrepare, MyClassDto .class);
DocumentDto signedDocument = documentService.signDocument(documentDto);
returnValue = modelMapper.map(signedDocument, DocumentRest.class);
return returnValue;
}
My DTO class work fine and retrieve the OptionClass datas, but concerning the second Class, i obtain null as value, while i try to print it out in the service layer.
Your ConstantClass should be a Bean or a Component (as #cassiomolin says in comments)
#Component
public class ConstantClass {
private String hostName;
private String pathStart;
public ConstantClass (#Value("${api.url}") String url, #Value("${sign.path}") String path ) {
this.hostName = url;
this.pathStart = path;
}
// getters...
Then you can easily inject this component in your Controller and use it.
#Controller
public class YourController(){
private ConstantClass constantClass;
public YourController(ConstantClass constantClass){
this.constantClass = constantClass;
}
#PostMapping("...")
public MyClass post(.....){
.....
MyClass myclass = new MyClass(this.constantClass,...)
.....
}
}
note that Spring can autowire #Value and #Component, ... via the constructor; that can be very useful when you do unit-testing
I try to initialize a Map in my SpringBoot application but I am doing something wrong.
My config.properties:
myFieldMap.10000.fieldName=MyFieldName
myFieldMap.10000.fieldName2=MyFieldName2
myFieldMap.10001.fieldName=MyFieldName
myFieldMap.10001.fieldName2=MyFieldName2
myFieldMap.10002.fieldName=MyFieldName
myFieldMap.10003.fieldName2=MyFieldName2
...
(Isn't it possible to use some kind of bracket notation like myFieldMap[10001].fieldName for maps (I saw it used for lists).
I tried with my MyConfig.class:
#PropertySource("classpath:config.properties")
#Component
public class MyConfig {
private java.util.Map<Integer, MyMapping> theMappingsMap = new HashMap<Integer, MyMapping>();
public Map<String, MyMapping> getTheMappingsMap() {
return theMappingsMap;
}
public void setTheMappingsMap(Map<String, MyMapping> theMappingsMap) {
this.theMappingsMap= theMappingsMap;
}
public class MyMapping {
private String fieldName;
private String fieldName2;
public String getFieldName() {
return fieldName;
}
public String getFieldName2() {
return fieldName2;
}
public void setFieldName(final String fieldName) {
this.fieldName = fieldName;
}
public void setFieldName2(final String fieldName) {
this.fieldName2 = fieldName;
}
}
}
How do I have to adapt my code to let SpringBoot initialize my configuration (Map) with the definitions in the config.properties file?
You are missing #ConfigurationProperties annotation. Try this
#PropertySource("classpath:config.properties")
#Configuration
#ConfigurationProperties
public class MyConfig {
private java.util.Map<String, MyMapping> myFieldMap = new HashMap<>();
....
}
Another issue with your code is, if you want to make MyMapping class as an inner class of MyConfig, then you need to declare it as static. Or else you can make it as a separate class.
I have a locations.properties file which looks like this:
location.endpoint=testadres,andertestadres
location.test=teststring
I'm trying to read this config file with following class:
#Configuration
#PropertySource("classpath:locations.properties")
public class LocationProperties {
#Value("#{'${location.endpoint}'.split(',')}")
private List<String> locations;
#Value("${location.test}")
private String test;
public String getTest() {
return this.test;
}
public List<String> getLocations() {
return this.locations;
}
//To resolve ${} in #Value
#Bean
public static PropertySourcesPlaceholderConfigurer propertyConfigInDev() {
return new PropertySourcesPlaceholderConfigurer();
}
}
But whenever I try to get the strings with getLocations() or getTest() I get null?
Just add .properties or .yml file to your /resources folder. Example
# simple.yml
demo:
connection:
username: sample
sample: My text
and add POJO class
#Component
#ConfigurationProperties(
prefix = "demo.connection",
locations = "classpath:sample.yml"
)
public class SampleSettings {
private String sample;
private String username;
..Getters and Setters mandatory