#788125 : added some utility methods to ExpressionUtils

querydsl-core/src/main/java/com/mysema/query/types/ExpressionUtils.java

@@ -10,6 +10,8 @@ import java.util.List;
 
 import javax.annotation.Nullable;
 
+import com.mysema.query.QueryMetadata;
+
 
 /**
  * ExpressionUtils provides utilities for constructing common operation instances
@@ -19,6 +21,80 @@ import javax.annotation.Nullable;
  */
 public final class ExpressionUtils {
     
+    /**
+     * Create a new Constant expression
+     * 
+     * @param <T>
+     * @param value
+     * @return
+     */
+    public static <T> Expression<T> constant(T value) {
+        return new ConstantImpl<T>(value);    
+    }
+    
+    /**
+     * Create a new TemplateExpression
+     * 
+     * @param <T>
+     * @param cl
+     * @param template
+     * @param args
+     * @return
+     */
+    public static <T> Expression<T> template(Class<T> cl, String template, Expression<?>... args) {
+        return TemplateExpressionImpl.create(cl, template, args);
+    }
+    
+    /**
+     * Create a new SubQuery expression
+     * 
+     * @param <T>
+     * @param type
+     * @param metadata
+     * @return
+     */
+    public static <T> Expression<T> subQuery(Class<? extends T> type, QueryMetadata metadata) {
+        return new SubQueryExpressionImpl<T>(type, metadata);
+    }
+    
+    /**
+     * Create a new Operation expression
+     * 
+     * @param <T>
+     * @param type
+     * @param operator
+     * @param args
+     * @return
+     */
+    public static <T> Expression<T> operation(Class<? extends T> type, Operator<? super T> operator, Expression<?>... args) {
+        return OperationImpl.create(type, operator, args);
+    }
+    
+    /**
+     * Create a new variable Path expression
+     * 
+     * @param <T>
+     * @param type
+     * @param variable
+     * @return
+     */
+    public static <T> Expression<T> path(Class<? extends T> type, String variable) {
+        return new PathImpl<T>(type, PathMetadataFactory.forVariable(variable));
+    }
+    
+    /**
+     * Create a new property Path expression
+     * 
+     * @param <T>
+     * @param type
+     * @param parent
+     * @param property
+     * @return
+     */
+    public static <T> Expression<T> path(Class<? extends T> type, Path<?> parent, String property) {
+        return new PathImpl<T>(type, PathMetadataFactory.forProperty(parent, property));
+    }
+    
     /**
      * Create the intersection of the given arguments
      *