Add helper method for type casting

Author: wanglingsong

jsurfer-all/src/test/java/org/jsfr/json/Book.java

@@ -32,6 +32,8 @@ public class Book {
 
     private Double price;
 
+    private String isbn;
+
     public String getCategory() {
         return category;
     }
@@ -63,4 +65,12 @@ public Double getPrice() {
     public void setPrice(Double price) {
         this.price = price;
     }
+
+    public String getIsbn() {
+        return isbn;
+    }
+
+    public void setIsbn(String isbn) {
+        this.isbn = isbn;
+    }
 }

jsurfer-all/src/test/java/org/jsfr/json/JsonSimpleParserTest.java

@@ -16,6 +16,13 @@ public void setUp() throws Exception {
         surfer = new JsonSurfer(JsonSimpleParser.INSTANCE, provider);
     }
 
+    @Ignore
+    @Override
+    public void testTypeCasting() throws Exception {
+        // ignore
+    }
+
+    @Ignore
     @Override
     public void testTypeBindingOne() throws Exception {
         // ignore

jsurfer-all/src/test/java/org/jsfr/json/JsonSurferTest.java

@@ -38,7 +38,7 @@
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.Reader;
-import java.nio.charset.StandardCharsets;
+import java.nio.charset.Charset;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -64,6 +64,35 @@ public void onValue(Object value, ParsingContext context) {
         }
     };
 
+    @Test
+    public void testTypeCasting() throws Exception {
+        surfer.configBuilder()
+                .bind("$.store.book[*]", new JsonPathListener() {
+                    @Override
+                    public void onValue(Object value, ParsingContext context) {
+                        assertNotNull(context.cast(value, Book.class));
+                    }
+                })
+                .bind("$.expensive", new JsonPathListener() {
+                    @Override
+                    public void onValue(Object value, ParsingContext context) {
+                        assertEquals(10L, context.cast(value, Long.class).longValue());
+                    }
+                })
+                .bind("$.store.book[0].price", new JsonPathListener() {
+                    @Override
+                    public void onValue(Object value, ParsingContext context) {
+                        assertEquals(8.95d, context.cast(value, Double.class), 0);
+                    }
+                })
+                .bind("$.store.book[1].title", new JsonPathListener() {
+                    @Override
+                    public void onValue(Object value, ParsingContext context) {
+                        assertEquals("Sword of Honour", context.cast(value, String.class));
+                    }
+                }).buildAndSurf(read("sample.json"));
+    }
+
     @Test
     public void testWildcardAtRoot() throws Exception {
         Collection<Object> collection = surfer.collectAll("[\n" +
@@ -90,8 +119,8 @@ public void testTypeBindingOne() throws Exception {
     @Test
     public void testTypeBindingCollection() throws Exception {
         Reader reader = read("sample.json");
-        Collection<Book> book = surfer.collectAll(reader, Book.class, JsonPathCompiler.compile("$..book[0,1]"));
-        assertEquals(2, book.size());
+        Collection<Book> book = surfer.collectAll(reader, Book.class, JsonPathCompiler.compile("$..book[*]"));
+        assertEquals(4, book.size());
         assertEquals("Nigel Rees", book.iterator().next().getAuthor());
     }
 
@@ -393,11 +422,11 @@ public void testAnyIndex() throws Exception {
     }
 
     protected Reader read(String resourceName) throws IOException {
-        return new InputStreamReader(Resources.getResource(resourceName).openStream(), StandardCharsets.UTF_8);
+        return new InputStreamReader(Resources.getResource(resourceName).openStream(), Charset.forName("UTF-8"));
     }
 
     protected String readAsString(String resourceName) throws IOException {
-        return Resources.toString(Resources.getResource(resourceName), StandardCharsets.UTF_8);
+        return Resources.toString(Resources.getResource(resourceName), Charset.forName("UTF-8"));
     }
 
     @Test

jsurfer-core/src/main/java/org/jsfr/json/ParsingContext.java

@@ -85,4 +85,12 @@ public interface ParsingContext {
      */
     <T> T load(String key, Class<T> tClass);
 
+    /**
+     * @param object object to cast
+     * @param tClass type
+     * @param <T>    type
+     * @return casted object
+     */
+    <T> T cast(Object object, Class<T> tClass);
+
 }

jsurfer-core/src/main/java/org/jsfr/json/SurfingContext.java

@@ -276,6 +276,11 @@ public <T> T load(String key, Class<T> tClass) {
         return this.transientMap != null ? tClass.cast(this.transientMap.get(key)) : null;
     }
 
+    @Override
+    public <T> T cast(Object object, Class<T> tClass) {
+        return (T) this.config.getJsonProvider().cast(object, tClass);
+    }
+
     public boolean shouldBreak() {
         return this.stopped || this.paused;
     }