How to use

getValue

method

in

org.springframework.expression.Expression

@Override
public String getValue(Object rootObject) throws EvaluationException {
  StringBuilder sb = new StringBuilder();
  for (Expression expression : this.expressions) {
    String value = expression.getValue(rootObject, String.class);
    if (value != null) {
      sb.append(value);
    }
  }
  return sb.toString();
}

@Test
public void indexIntoPropertyContainingListOfList() {
  List<List<Integer>> property = new ArrayList<>();
  property.add(Arrays.asList(3));
  this.parameterizedListOfList = property;
  SpelExpressionParser parser = new SpelExpressionParser();
  Expression expression = parser.parseExpression("parameterizedListOfList[0]");
  assertEquals("java.util.Arrays$ArrayList<java.lang.Integer>", expression.getValueTypeDescriptor(this).toString());
  assertEquals(property.get(0), expression.getValue(this));
  expression = parser.parseExpression("parameterizedListOfList[0][0]");
  assertEquals(3, expression.getValue(this));
}

@Test
public void testOtherOperators() throws Exception {
  // evaluates to false
  boolean falseValue = parser.parseExpression("'xyz' instanceof T(int)").getValue(Boolean.class);
  assertFalse(falseValue);
  // evaluates to true
  boolean trueValue = parser.parseExpression("'5.00' matches '^-?\\d+(\\.\\d{2})?$'").getValue(Boolean.class);
  assertTrue(trueValue);
  //evaluates to false
  falseValue = parser.parseExpression("'5.0067' matches '^-?\\d+(\\.\\d{2})?$'").getValue(Boolean.class);
  assertFalse(falseValue);
}

@SuppressWarnings("unchecked")
@Test
public void resolveCollectionElementType() {
  listNotGeneric = new ArrayList(2);
  listNotGeneric.add(5);
  listNotGeneric.add(6);
  SpelExpressionParser parser = new SpelExpressionParser();
  Expression expression = parser.parseExpression("listNotGeneric");
  assertEquals("@org.springframework.expression.spel.IndexingTests$FieldAnnotation java.util.ArrayList<?>", expression.getValueTypeDescriptor(this).toString());
  assertEquals("5,6", expression.getValue(this, String.class));
}

@Test
public void ternaryWithBooleanReturn_SPR12271() {
  expression = parser.parseExpression("T(Boolean).TRUE?'abc':'def'");
  assertEquals("abc", expression.getValue());
  assertCanCompile(expression);
  assertEquals("abc", expression.getValue());
  expression = parser.parseExpression("T(Boolean).FALSE?'abc':'def'");
  assertEquals("def", expression.getValue());
  assertCanCompile(expression);
  assertEquals("def", expression.getValue());
}

@Test
public void indexIntoPropertyContainingList() {
  List<Integer> property = new ArrayList<>();
  property.add(3);
  this.parameterizedList = property;
  SpelExpressionParser parser = new SpelExpressionParser();
  Expression expression = parser.parseExpression("parameterizedList");
  assertEquals("java.util.ArrayList<java.lang.Integer>", expression.getValueTypeDescriptor(this).toString());
  assertEquals(property, expression.getValue(this));
  expression = parser.parseExpression("parameterizedList[0]");
  assertEquals(3, expression.getValue(this));
}

@Test
public void testResolvingString() {
  Class<?> stringClass = parser.parseExpression("T(String)").getValue(Class.class);
  assertEquals(String.class, stringClass);
}

@Test
public void emptyList() {
  listOfScalarNotGeneric = new ArrayList();
  SpelExpressionParser parser = new SpelExpressionParser();
  Expression expression = parser.parseExpression("listOfScalarNotGeneric");
  assertEquals("java.util.ArrayList<?>", expression.getValueTypeDescriptor(this).toString());
  assertEquals("", expression.getValue(this, String.class));
}

@Test
public void methodReference_simpleInstanceMethodOneArgReturnPrimitive2() throws Exception {
  expression = parser.parseExpression("charAt(2)");
  char resultI = expression.getValue("abc", Character.TYPE);
  assertEquals('c', resultI);
  assertCanCompile(expression);
  char resultC = expression.getValue("abc", Character.TYPE);
  assertEquals('c', resultC);
}

@Test
public void testAccessingPropertyOfClass() {
  Expression expression = parser.parseExpression("name");
  Object value = expression.getValue(new StandardEvaluationContext(String.class));
  assertEquals("java.lang.String", value);
}

@Test(expected = SpelEvaluationException.class)
public void noGetClassAccess() {
  EvaluationContext context = SimpleEvaluationContext.forReadOnlyDataBinding().build();
  parser.parseExpression("'a'.class.name").getValue(context);
}

@Test
@SuppressWarnings("unchecked")
public void SPR11494() {
  Expression exp = new SpelExpressionParser().parseExpression("T(java.util.Arrays).asList('a','b')");
  List<String> list = (List<String>) exp.getValue();
  assertThat(list.size(), is(2));
}

@Test
public void methodReference_literalArguments_int() throws Exception {
  Expression expression = parser.parseExpression("'abcd'.substring(1,3)");
  String resultI = expression.getValue(new TestClass1(), String.class);
  assertCanCompile(expression);
  String resultC = expression.getValue(new TestClass1(), String.class);
  assertEquals("bc", resultI);
  assertEquals("bc", resultC);
}

@Test
public void SPR9486_subtractFloatWithDouble() {
  Number expectedNumber = 10.21f - 10.2;
  ExpressionParser parser = new SpelExpressionParser();
  StandardEvaluationContext context = new StandardEvaluationContext();
  Expression expression = parser.parseExpression("10.21f - 10.2");
  Number result = expression.getValue(context, null, Number.class);
  assertEquals(expectedNumber, result);
}

@Test
public void SPR9486_floatLessThanOrEqualFloat() {
  Boolean expectedNumber = -10.21f <= -10.22f;
  ExpressionParser parser = new SpelExpressionParser();
  StandardEvaluationContext context = new StandardEvaluationContext();
  Expression expression = parser.parseExpression("-10.21f <= -10.22f");
  Boolean result = expression.getValue(context, null, Boolean.class);
  assertEquals(expectedNumber, result);
}

@Test
public void SPR10210() {
  StandardEvaluationContext context = new StandardEvaluationContext();
  context.setVariable("bridgeExample", new org.springframework.expression.spel.spr10210.D());
  Expression parseExpression = parser.parseExpression("#bridgeExample.bridgeMethod()");
  parseExpression.getValue(context);
}

@Test
public void nullLiteral() throws Exception {
  expression = parser.parseExpression("null");
  Object resultI = expression.getValue(new TestClass1(), Object.class);
  assertCanCompile(expression);
  Object resultC = expression.getValue(new TestClass1(), Object.class);
  assertEquals(null, resultI);
  assertEquals(null, resultC);
  assertEquals(null, resultC);
}

@Test
@SuppressWarnings("rawtypes")
public void SPR12522() {
  SpelExpressionParser parser = new SpelExpressionParser();
  Expression expression = parser.parseExpression("T(java.util.Arrays).asList('')");
  Object value = expression.getValue();
  assertTrue(value instanceof List);
  assertTrue(((List) value).isEmpty());
}

private void checkTemplateParsing(String expression, ParserContext context, String expectedValue) {
  SpelExpressionParser parser = new SpelExpressionParser();
  Expression expr = parser.parseExpression(expression, context);
  assertEquals(expectedValue, expr.getValue(TestScenarioCreator.getTestEvaluationContext()));
}

@Test
public void SPR11609() {
  StandardEvaluationContext sec = new StandardEvaluationContext();
  sec.addPropertyAccessor(new MapAccessor());
  Expression exp = new SpelExpressionParser().parseExpression(
      "T(org.springframework.expression.spel.SpelReproTests$MapWithConstant).X");
  assertEquals(1, exp.getValue(sec));
}