Hi Suchand, Somehow the table you wanted to present got deformated. Could you please provide me a web reference to it?
Thanks in advance. Cheers On Dec 1, 5:15 am, Suchand Ghosh <[email protected]> wrote: > I think you r looking for: > > Mapping types > > The following table shows the mapping of types between Java and native code. > Native Type Java Language Type Description Type signature unsigned char > jboolean unsigned 8 bits Z signed char jbyte signed 8 bits B unsigned short > jchar unsigned 16 bits C short jshort signed 16 bits S long jint signed 32 > bits I > > long long > __int64 > jlong signed 64 bits J float jfloat 32 bits F double jdouble 64 bits D > > In addition, the signature "L fully-qualified-class ;" would mean the class > uniquely specified by that name; e.g., the signature "Ljava/lang/String;" > refers to the class java.lang.String. Also, prefixing [ to the signature > makes the array of that type; for example, [I means the int array type. > > Here, these types are interchangeable. You can use jint where you normally > use an int, and vice-versa, without any > typecasting<http://en.wikipedia.org/wiki/Typecast>required. > > However, mapping between Java Strings and arrays to native strings and > arrays is different. If you use a jstring in where a char * would be, your > code could crash the JVM. > Cheers... > > BR, > Chand > > On Tue, Dec 1, 2009 at 2:14 AM, fadden <[email protected]> wrote: > > On Nov 30, 9:08 am, bacchus <[email protected]> wrote: > > > I'm looking for specific information about Android JNI Call Bridge. > > > The one that exists does not suffices my needs. > > > The "JNI call bridge" is a bit of code that converts an array of 32- > > bit values into C-style arguments. It takes into account host- > > specific calling conventions, notably which arguments go into which > > registers (by type or position), which go onto the stack, and how > > values should be padded. > > > The sources include a version based on libffi (slow) and a few CPU- > > specific implementations (ARM EABI, SH4, x86). > > > > I would like to understand the mappings performed between C/C++ data > > > types and Java data types. > > > > As an example, I would like to understand where and how the VMRuntime > > > object is defined and mapped. > > > This is beyond the scope of the JNI function call interface. If you > > want higher-level object to interact more directly, you may need to > > look into Cygnus CNI (requires compiler support) or JNA (convenience, > > but at a price). > > > Was there something specific about VMRuntime that interested you? > > > -- > > You received this message because you are subscribed to the Google > > Groups "Android Developers" group. > > To post to this group, send email to [email protected] > > To unsubscribe from this group, send email to > > [email protected]<android-developers%[email protected]> > > For more options, visit this group at > >http://groups.google.com/group/android-developers?hl=en > > -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
