We Keep Coding

Can you override a library's Spring property placeholders?

We are working on moving our application to use only Spring-Boot application.properties files. The old way we were doing was that each library/dependency would have their properties stored in a dedicated properties file like res/environment/some-library-override.properties. The values would then be retrieved in the library using #Value("$some-library-{PROPERTY_NAME}").
However, since moving all of these override properties to dedicated application.properties files, it is no longer resolving the properties and we get errors like java.lang.NumberFormatException: For input string: "$some-library-{PROPERTY_NAME}".
I assume this is because it is still expecting the property to be in that dedicated properties file.
Is there a solution to this that doesn't involve modifying the library/dependency? Is it possible to have it ignore the prefix and only look for the PROPERTY_NAME in the application.properties files?

if you have declared propertie var likeproperty.name=XXXX or added environment var like PROPERTY_NAME=XXXX.
you need to use this way
#Value("some-library-${property.name}")
// will inject value "some-library" + "XXXX"

Java bean gets property name instead of value

I have a .properties file with bunch of properties in it. Here's an example:
mes.mail.debug=true
cookie.sso.domain = .stuffStuff.com
blabla.endpoint = blabla.com
test.value.property = myValue
The problem is with the last one (Which I have just added to the project we're working on).
I read the properties using #Value("${PropertyName}") annotation and it was working perfectly until lately, when I use the same thing, the variable gets the propertyName instead of its value:
#Value("${test.value.property}")
private String mProperty;
so, mProperty gets "test.value.property" where what I'm looking for is for it to get "myValue".
What's happening exactly? Is there something wrong with my project? I have tested in my friend's computer and it works perfectly.
By the way, i'm using Spring Tool Suite.
EDIT: It turns out that it doesn't detect the changes I make in the properties file. So if I change an old property's value; it acts as if nothing happened.
Does anyone has any idea why it's doing like this?

When you declare a Property Placeholder Configurer to load the properties files, you can set it to ignore unresolvable placeholders.
This means that if the property you are injecting with #Value is not found, its name (or key) will be assigned to the variable.
In your case, this option is enabled and the file that has been loaded by the application is not the one you are editing.
To see from where the file is been loaded, check the placeholder configurer location property.

Spring properties that depend on other properties

I would like to have properties, that I can reference via #Value in spring beans, that can only be created dependend on other properties.
In particular I am having a property, that describes the file system location of a directory.
myDir=/path/to/mydir
And by convention, there is a file in that directory, that is always called myfile.txt.
Now i want to have access to both, the directory and the file, via #Value annotations inside my beans. And sometimes I want to access them as Strings, sometimes as java.io.Files and sometimes as org.springframework.core.io.FileSystemResource (which by the way works very well out of the box!). But because of that concatenating Strings on demand is not an option.
So what I of course could do is just declare both, but I would end up with
myDir=/path/to/mydir
myFile/path/to/mydir/myfile.txt
and I would like to avoid that.
So I came up with an #Configuration class, that takes the property and adds it as new PropertySource:
#Autowired
private ConfigurableEnvironment environment;
#Value("${myDir}")
private void addCompleteFilenameAsProperty(Path myDir) {
Path absoluteFilePath = myDir.resolve("myfile.txt");
Map<String, Object> props = new HashMap<>();
props.put("myFile, absoluteFilePath.toString());
environment.getPropertySources().addFirst(new MapPropertySource("additional", props));
}
As you can see, in my context I even created a PropertyEditor, that can convert to java.nio.file.Paths.
Now the problem is, that for some reason, this "works on my machine" (in my IDE), but does not run on the intended target environment. There I get
java.lang.IllegalArgumentException: Could not resolve placeholder 'myFile' in string value "${myFile}"

Spring can combine properties
myDir=/path/to/mydir
myFile=${myDir}/myfile.txt
You can also use a default value without defining your myFile in the properties at first:
Properties file
myDir=/path/to/mydir
In class:
#Value("#{myFile:${myDir}/myfile.txt}")
private String myFileName;

Spring expressions can be used to refer the properties.
In my example it was
query-parm=QueryParam1=
query-value=MyParamaterValue
Now while binding them in Spring Bean.
#Configuration
public class MyConfig {
#Value("${query-param}${query-value}")
private String queryString;
}
Above code will inject QueryParam1=MyParamaterValue to the variable queryString.

Spring 4 #Value where property default is a java system property

In Spring 4, using the #Value annotation, what is the right way to specify a system property as a default if a specified property does not exists?
Whereas this works for the no-default case:
#Value("${myapp.temp}")
private String tempDirectory;
This doesn't work when I need a default:
#Value("#{myapp.temp ?: systemProperties.java.io.tmpdir}")
private String tempDirectory;
Nor does this:
#Value("#{myapp.temp ?: systemProperties(java.io.tmpdir)}")
private String tempDirectory;
Both of these give me an exception at the time Spring is trying to create the bean:
org.springframework.beans.factory.BeanCreationException: Error creating bean
with name 'configurationService': Invocation of init method failed;
nested exception is java.lang.NullPointerException
Can this be done?

I tried the following and it worked for me:
#Value("${myapp.temp:#{systemProperties['java.io.tmpdir']}}")
private String tempDirectory;
The missing parts for you I believe was not using ?: and needing the #{}. According to this answer:
${...} is the property placeholder syntax. It can only be used to dereference properties.
#{...} is SpEL syntax, which is far more capable and complex. It can also handle property placeholders, and a lot more besides.
So basically what is happening is we are telling Spring to first interpret myapp.temp as property placeholder syntax by using the ${} syntax. We then use : instead of ?: (which is called the Elvis operator) since the elvis operator only applies to Spring Expression Language expressions, not property placeholder syntax. The third part of our statement is #{systemProperties['java.io.tmpdir']} which is telling Spring to interpret the next expression as a Spring Expression and allows us to get system properties.

Try systemProperties['java.io.tmpdir'].
It's a map, so if the key has a dot in the name, you should use [..]

For me it only works with different property-names (being property.name.a a key with a value in my application.properties and property.name.b a Environment-Variable) like:
#Value("${property.name.a:${property.name.b}}")
The same names didn´t work for me like expected (loading the default, when the first property isn´t present), e.g.:
#Value("${property.name.a:${property.name.a}}")

Spring #Value from .properties file null in debug eclipse

The purpose of my code is to load some settings value from a *.properties file so that I later can use these values in some if-statements in my code. I want to load in some list-structure, but since that seems hard, an array will do. I have not really gotten that far, since I am stuck at the trivial matter of loading just a String from the properties file.
When I try to debug my code that is using some spring specific data. I get some interesting behaviour, pointing on the definition in the code right above the breakpoint gives me that the variable value is null.
#Value(value = "${ViewableReportFilter.allStates.verify}")
String verifyStringStates;
public ViewableReportFilter() {
viewStates = null;
log.debug("Read in properties for states: verify:" + verifyStringStates);
/*BREAKPOINT HERE*/
in my my.properties file:
ViewableReportFilter.allStates.verify=ONHOLD
And my config to use the properties-file:
<context:property-placeholder location="classpath:properties/my.properties" order="1" ignore-unresolvable="true" />

Spring can't set the fields of an object before that object is created. The first thing Spring does is use reflection to instantiate your class. It'll use either Class#newInstance() or use Constructor#newInstance() depending on the context. Only when the constructor has finished its work and returned can Spring, again using reflection, set the value of fields.
An alternative is to put a #Value annotated parameter in the constructor parameter list and set your field inside your constructor from the argument that's given to it by Spring.
public ViewableReportFilter(#Value String verify) {
this.verifyStringStates = verify;
...
Go through the Spring documentation for its IoC container. It explains all of this in much detail.

Updated the constructor, and added Autowire annotation. No changes in the properties file, no XML.
String arrayOfStrings;
#Autowired
public ViewableReportFilter(
#Value("${TMSViewableReportFilter.allStates.verify}") String[] verifyStringStates) {
arrayOfStrings = verifyStringStates;
public logViewableReportFilter() {
log.debug("Read in properties for states: verify:" + arrayOfString);
}

Try using this:
#Value(value = "${allStates.verify}")
And in your property my.properties:
allStates.verify=ONHOLD