There are other functional interfaces you may be interested in, for example: Supplier<T> if you want to return a value of T without passing any parameters Function<T,R> if you want to pass a value of T and return a value of R Consumer<T> if you want to pass value T as a parameter and return void
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Run npm init to create package.json file for the application npm init Then install Express in the app directory app and save it in the dependancies list npm install express –save Generate a self-signed certificate cd sslcert openssl req -nodes -new -x509 -keyout server.key -out server.cert Enable HTTPS in Express (index.js) var fs = require(‘fs’); […]
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import org.junit.Test; import java.util.HashMap; import java.util.Map; public class FlatmapTest { @Test public void test() { Map<Integer, Map<String, Integer>> map = new HashMap<>(); Map<String, Integer> map1 = new HashMap<>(); map1.put(“a”, 1); map1.put(“b”, 2); map.put(1, map1); map1 = new HashMap<>(); map1.put(“c”, 3); map1.put(“d”, 4); map.put(2, map1); Integer sum = map.values().stream() .map(Map::values) .flatMap(i -> i.stream()) .reduce(0, Integer::sum); System.out.println(sum); […]
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public class Clazz { int type; int value; BigDecimal dValue; public Clazz(int type, BigDecimal dValue) { this.type = type; this.dValue = dValue; } public Clazz(int type, int value) { this.type = type; this.value = value; } public int getType() { return type; } public int getValue() { return value; } public BigDecimal getDValue() { return […]
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In this article we see the meaning of @Mock and @InjectMock annotations. Below the class we are going to Mock. @Mock annotation Here the class we are going to test. Now the test case. As you can see mocked instance mockedService is passed as constructor argument to declared instance of ServiceToTest. @InjectMock annotation Below the […]
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Considering the case when a call to a web service with Spring RestTemplate return an error response and we want to handle this error as a Java object. RestTemplate error responses can be handled implementing the class ResponseErrorHandler. Considering a JSON response error like the following lets see how to transform it in a This […]
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Sometimes can be useful extract some specific attribute from a JSON string. This can be done easily with com.google.code.gson library in this way. Let’s consider the following JSON: This is the maven dependancy: And finally the code to extract the value of “field2”:
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This article shows how to use Springs RestTemplate to consume a RESTful Service secured with Basic Authentication. Since Spring 5.1.1 BasicAuthenticationInterceptor has been introduced for Basic Authentication. Code above will automatically add Authorization: Basic dXNlcm5hbWU6cGFzc3dvcmQ= header.
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