Examples of org.apache.velocity.tools.generic.FieldTool

Package org.apache.velocity.tools.generic

Examples of org.apache.velocity.tools.generic.FieldTool

org.apache.velocity.tools.generic.FieldTool

This is a simple tools class to allow easy access to static fields in a class, such as string constants from within a template. Velocity will not introspect for class fields (and won't in the future :), but writing setter/getter methods to do this is a pain, so use this if you really have to access fields.

 Example uses in a template: ## here we access a constant in a class include in the configuration $field.COUNTER_NAME ## here we dynamically lookup a class' fields to find another constant $field.in("org.com.SomeClass").ANOTHER_CONSTANT ## here we pass an object instance in (an Integer in this case) and ## retrieve a static constant from that instance's class $field.in(0).MIN_VALUE ## by default, once we've searched a class' fields, those fields stay ## available in the tool (change this by storeDynamicLookups="false") ## so here we get another constant from the Integer class $field.MAX_VALUE Example tools.xml config: <tools> <toolbox scope="application"> <tool class="org.apache.velocity.tools.generic.FieldTool" include="org.apache.velocity.runtime.RuntimeConstants,com.org.MyConstants"/> </toolbox> </tools>

Right now, this tool only gives access to public static fields. It seems that anything else is too dangerous. This is for convenient access to 'constants'. If you have fields that aren't static, handle them by explicitly placing them into the context or writing a getter method. @author Geir Magnusson Jr. @author Nathan Bubna @since VelocityTools 2.0 @version $Id: FieldTool.java 463298 2006-10-12 16:10:32Z henning $

    }


    public static String MUTABLE_FIELD = "foo";


    public @Test void testFieldTool() {
        FieldTool fieldTool = (FieldTool)toolbox.get("field");
        assertNotNull(fieldTool);


        // read a constant from the configured included Class
        assertEquals(Integer.MAX_VALUE, fieldTool.get("MAX_VALUE"));


        // read a constant from java.lang.Boolean and make sure it is the same
        assertSame(Boolean.TRUE, fieldTool.in("java.lang.Boolean").get("TRUE"));


        // tell it to read constants from a non-existant class
        // (which should return null)
        assertNull(fieldTool.in("no.such.Class"));


        // tell field tool to read constants from this instance's Class
        // (which should NOT return null)
        assertNotNull(fieldTool.in(this));
        assertEquals(MUTABLE_FIELD, fieldTool.get("MUTABLE_FIELD"));
        // grab the mutable field
        String foo = MUTABLE_FIELD;
        // change it
        MUTABLE_FIELD = MUTABLE_FIELD + MUTABLE_FIELD;
        // make sure it changed
        assertFalse(foo.equals(MUTABLE_FIELD));
        // make sure the fieldtool recognized that it changed
        assertEquals(MUTABLE_FIELD, fieldTool.get("MUTABLE_FIELD"));


        // pass a full field path to the get() method
        assertEquals(Long.MIN_VALUE, fieldTool.get("java.lang.Long.MIN_VALUE"));
    }

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    }


    public static String MUTABLE_FIELD = "foo";


    public @Test void testFieldTool() {
        FieldTool fieldTool = (FieldTool)toolbox.get("field");
        assertNotNull(fieldTool);


        // read a constant from the configured included Class
        assertEquals(Integer.MAX_VALUE, fieldTool.get("MAX_VALUE"));


        // read a constant from java.lang.Boolean and make sure it is the same
        assertSame(Boolean.TRUE, fieldTool.in("java.lang.Boolean").get("TRUE"));


        // tell it to read constants from a non-existant class
        // (which should return null)
        assertNull(fieldTool.in("no.such.Class"));


        // tell field tool to read constants from this instance's Class
        // (which should NOT return null)
        assertNotNull(fieldTool.in(this));
        assertEquals(MUTABLE_FIELD, fieldTool.get("MUTABLE_FIELD"));
        // grab the mutable field
        String foo = MUTABLE_FIELD;
        // change it
        MUTABLE_FIELD = MUTABLE_FIELD + MUTABLE_FIELD;
        // make sure it changed
        assertFalse(foo.equals(MUTABLE_FIELD));
        // make sure the fieldtool recognized that it changed
        assertEquals(MUTABLE_FIELD, fieldTool.get("MUTABLE_FIELD"));


        // pass a full field path to the get() method
        assertEquals(Long.MIN_VALUE, fieldTool.get("java.lang.Long.MIN_VALUE"));
    }

View Full Code Here

    }


    public static String MUTABLE_FIELD = "foo";


    public @Test void testFieldTool() {
        FieldTool fieldTool = (FieldTool)toolbox.get("field");
        assertNotNull(fieldTool);


        // read a constant from the configured included Class
        assertEquals(Integer.MAX_VALUE, fieldTool.get("MAX_VALUE"));


        // read a constant from java.lang.Boolean and make sure it is the same
        assertSame(Boolean.TRUE, fieldTool.in("java.lang.Boolean").get("TRUE"));


        // tell it to read constants from a non-existant class
        // (which should return null)
        assertNull(fieldTool.in("no.such.Class"));


        // tell field tool to read constants from this instance's Class
        // (which should NOT return null)
        assertNotNull(fieldTool.in(this));
        assertEquals(MUTABLE_FIELD, fieldTool.get("MUTABLE_FIELD"));
        // grab the mutable field
        String foo = MUTABLE_FIELD;
        // change it
        MUTABLE_FIELD = MUTABLE_FIELD + MUTABLE_FIELD;
        // make sure it changed
        assertFalse(foo.equals(MUTABLE_FIELD));
        // make sure the fieldtool recognized that it changed
        assertEquals(MUTABLE_FIELD, fieldTool.get("MUTABLE_FIELD"));


        // pass a full field path to the get() method
        assertEquals(Long.MIN_VALUE, fieldTool.get("java.lang.Long.MIN_VALUE"));
    }

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org.apache.velocity.tools.test.whitebox.GenericToolsTests

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