Add string lastindexof

Author: dlunch

java_runtime/src/classes/java/lang/string.rs

@@ -60,6 +60,7 @@ impl String {
                 JavaMethodProto::new("indexOf", "(II)I", Self::index_of_from, Default::default()),
                 JavaMethodProto::new("indexOf", "(Ljava/lang/String;)I", Self::index_of_string, Default::default()),
                 JavaMethodProto::new("indexOf", "(Ljava/lang/String;I)I", Self::index_of_string_from, Default::default()),
+                JavaMethodProto::new("lastIndexOf", "(I)I", Self::last_index_of, Default::default()),
                 JavaMethodProto::new("trim", "()Ljava/lang/String;", Self::trim, Default::default()),
                 JavaMethodProto::new("startsWith", "(Ljava/lang/String;)Z", Self::starts_with, Default::default()),
                 JavaMethodProto::new("startsWith", "(Ljava/lang/String;I)Z", Self::starts_with_offset, Default::default()),
@@ -373,6 +374,21 @@ impl String {
         Ok(index.unwrap_or(-1))
     }
 
+    async fn last_index_of(jvm: &Jvm, _: &mut RuntimeContext, this: ClassInstanceRef<Self>, ch: i32) -> Result<i32> {
+        tracing::debug!("java.lang.String::lastIndexOf({:?}, {:?})", &this, ch);
+
+        let this_string = JavaLangString::to_rust_string(jvm, &this.clone()).await?;
+
+        let index = this_string
+            .chars()
+            .collect::<Vec<_>>() // TODO i think we don't need collect..
+            .into_iter()
+            .rposition(|x| x as u32 == ch as u32)
+            .map(|x| x as i32);
+
+        Ok(index.unwrap_or(-1))
+    }
+
     async fn trim(jvm: &Jvm, _: &mut RuntimeContext, this: ClassInstanceRef<Self>) -> Result<ClassInstanceRef<Self>> {
         tracing::debug!("java.lang.String::trim({:?})", &this);
 

java_runtime/tests/classes/java/lang/test_string.rs

@@ -130,3 +130,21 @@ async fn test_starts_with() -> Result<()> {
 
     Ok(())
 }
+
+#[tokio::test]
+async fn test_last_index_of() -> Result<()> {
+    let jvm = test_jvm().await?;
+
+    let string = JavaLangString::from_rust_string(&jvm, "456 가나다 456").await?;
+
+    let index: i32 = jvm.invoke_virtual(&string, "lastIndexOf", "(I)I", (b'4' as i32,)).await?;
+    assert_eq!(index, 8);
+    let index: i32 = jvm.invoke_virtual(&string, "lastIndexOf", "(I)I", (b'5' as i32,)).await?;
+    assert_eq!(index, 9);
+    let index: i32 = jvm.invoke_virtual(&string, "lastIndexOf", "(I)I", (b'6' as i32,)).await?;
+    assert_eq!(index, 10);
+    let index: i32 = jvm.invoke_virtual(&string, "lastIndexOf", "(I)I", (b'7' as i32,)).await?;
+    assert_eq!(index, -1);
+
+    Ok(())
+}