Merge pull request #5548 from Doha2012/master

custom binder example

spring-boot-ops/src/main/java/org/baeldung/boot/config/WebConfig.java

@@ -1,16 +1,17 @@
 package org.baeldung.boot.config;
 
+import java.util.List;
+
 import org.baeldung.boot.converter.GenericBigDecimalConverter;
+import org.baeldung.boot.converter.StringToAbstractEntityConverterFactory;
 import org.baeldung.boot.converter.StringToEmployeeConverter;
-import org.baeldung.boot.converter.StringToEnumConverterFactory;
+import org.baeldung.boot.converter.StringToEnumConverter;
 import org.baeldung.boot.web.resolver.HeaderVersionArgumentResolver;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.format.FormatterRegistry;
 import org.springframework.web.method.support.HandlerMethodArgumentResolver;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 
-import java.util.List;
-
 @Configuration
 public class WebConfig implements WebMvcConfigurer {
 
@@ -22,7 +23,8 @@ public class WebConfig implements WebMvcConfigurer {
     @Override
     public void addFormatters(FormatterRegistry registry) {
         registry.addConverter(new StringToEmployeeConverter());
-        registry.addConverterFactory(new StringToEnumConverterFactory());
+        registry.addConverter(new StringToEnumConverter());
+        registry.addConverterFactory(new StringToAbstractEntityConverterFactory());
         registry.addConverter(new GenericBigDecimalConverter());
     }
 }

spring-boot-ops/src/main/java/org/baeldung/boot/converter/StringToAbstractEntityConverterFactory.java

@@ -0,0 +1,39 @@
+package org.baeldung.boot.converter;
+
+import org.baeldung.boot.domain.AbstractEntity;
+import org.baeldung.boot.domain.Bar;
+import org.baeldung.boot.domain.Foo;
+import org.springframework.core.convert.converter.Converter;
+import org.springframework.core.convert.converter.ConverterFactory;
+
+public class StringToAbstractEntityConverterFactory implements ConverterFactory<String, AbstractEntity>{
+
+    @Override
+    public <T extends AbstractEntity> Converter<String, T> getConverter(Class<T> targetClass) {
+
+        return new StringToAbstractEntityConverter<>(targetClass);
+    }
+
+
+    private static class StringToAbstractEntityConverter<T extends AbstractEntity> implements Converter<String, T> {
+
+        private Class<T> targetClass;
+
+        public StringToAbstractEntityConverter(Class<T> targetClass) {
+            this.targetClass = targetClass;
+        }
+
+        @Override
+        public T convert(String source) {
+            long id = Long.parseLong(source);
+            if(this.targetClass == Foo.class) {
+                return (T) new Foo(id);
+            }
+            else if(this.targetClass == Bar.class) {
+                return (T) new Bar(id);
+            } else {
+                return null;
+            }
+        }
+    }
+}

spring-boot-ops/src/main/java/org/baeldung/boot/converter/StringToEnumConverter.java

@@ -0,0 +1,12 @@
+package org.baeldung.boot.converter;
+
+import org.baeldung.boot.domain.Modes;
+import org.springframework.core.convert.converter.Converter;
+
+public class StringToEnumConverter implements Converter<String, Modes> {
+
+    @Override
+    public Modes convert(String from) {
+        return Modes.valueOf(from);
+    }
+}

spring-boot-ops/src/main/java/org/baeldung/boot/converter/StringToEnumConverterFactory.java

@@ -1,27 +0,0 @@
-package org.baeldung.boot.converter;
-
-import org.springframework.core.convert.converter.Converter;
-import org.springframework.core.convert.converter.ConverterFactory;
-import org.springframework.stereotype.Component;
-
-@Component
-public class StringToEnumConverterFactory implements ConverterFactory<String, Enum> {
-
-    private static class StringToEnumConverter<T extends Enum> implements Converter<String, T> {
-
-        private Class<T> enumType;
-
-        public StringToEnumConverter(Class<T> enumType) {
-            this.enumType = enumType;
-        }
-
-        public T convert(String source) {
-            return (T) Enum.valueOf(this.enumType, source.trim());
-        }
-    }
-
-    @Override
-    public <T extends Enum> Converter<String, T> getConverter(final Class<T> targetType) {
-        return new StringToEnumConverter(targetType);
-    }
-}

spring-boot-ops/src/main/java/org/baeldung/boot/converter/controller/AbstractEntityController.java

@@ -0,0 +1,31 @@
+package org.baeldung.boot.converter.controller;
+
+import org.baeldung.boot.domain.Bar;
+import org.baeldung.boot.domain.Foo;
+import org.baeldung.boot.domain.Modes;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/string-to-abstract")
+public class AbstractEntityController {
+
+    @GetMapping("/foo/{foo}")
+    public ResponseEntity<Object> getStringToFoo(@PathVariable Foo foo) {
+        return ResponseEntity.ok(foo);
+    }
+    
+    @GetMapping("/bar/{bar}")
+    public ResponseEntity<Object> getStringToBar(@PathVariable Bar bar) {
+        return ResponseEntity.ok(bar);
+    }
+    
+    @GetMapping
+    public ResponseEntity<Object> getStringToMode(@RequestParam("mode") Modes mode) {
+        return ResponseEntity.ok(mode);
+    }
+}

spring-boot-ops/src/main/java/org/baeldung/boot/domain/AbstractEntity.java

@@ -0,0 +1,10 @@
+package org.baeldung.boot.domain;
+
+public abstract class AbstractEntity {
+
+    long id;
+    public AbstractEntity(long id){
+        this.id = id;
+    }
+    
+}

spring-boot-ops/src/main/java/org/baeldung/boot/domain/Bar.java

@@ -0,0 +1,29 @@
+package org.baeldung.boot.domain;
+
+public class Bar extends AbstractEntity {
+
+    private int value;
+    
+    public Bar(long id) {
+        super(id);
+    }
+
+    public Bar(long id, int value) {
+        super(id);
+        this.value = value;
+    }
+
+    public int getValue() {
+        return value;
+    }
+
+    public void setValue(int value) {
+        this.value = value;
+    }
+
+    @Override
+    public String toString() {
+        return "Bar [value=" + value + ", id=" + id + "]";
+    }
+    
+}

spring-boot-ops/src/main/java/org/baeldung/boot/domain/Foo.java

@@ -0,0 +1,31 @@
+package org.baeldung.boot.domain;
+
+import static org.apache.commons.lang3.RandomStringUtils.randomAlphanumeric;
+public class Foo extends AbstractEntity {
+
+    private String name;
+    
+    public Foo(long id) {
+        super(id);
+        name = randomAlphanumeric(4);
+    }
+
+    public Foo(long id, String name) {
+        super(id);
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public String toString() {
+        return "Foo [name=" + name + ", id=" + id + "]";
+    }
+    
+}