testApp.cpp

#include "testApp.h"

void testApp::setup()
{
    ofAddListener(httpUtils.newResponseEvent, this, &testApp::newResponse);
    httpUtils.start();

    ofxHttpForm form;

    form.action = "http://example.com/images/hoge.jpg";
    form.method = OFX_HTTP_GET;

    httpUtils.addForm(form);
}

void testApp::newResponse(ofxHttpResponse &response)
{
    FIMEMORY *hmem = NULL;
    FIBITMAP *bmp = NULL;

    hmem = FreeImage_OpemMemory((unsigned char *)response.responseBody.c_str(),
                                response.responseBody.size());
    if (hmem == NULL) {
        ofLog(OF_LOG_ERROR, "hmem is NULL.");
        return;
    }

    FREE_IMAGE_FORMAT fif = FreeImage_GetFileTypeFromMemory(hmem);
    bmp = FreeImage_LoadFromMemory(fif, hmem, 0);

    if (bmp == NULL) {
        ofLog(OF_LOG_ERROR, "bmp is NULL.");
        return;
    }

    FreeImage_Save(fif, bmp, ofToDataPath("thumb.jpg").c_str(), 0);
}

testApp.h

#include "ofMain.h"
#include "ofxHttpUtils.h"

class testApp:public ofBaseApp
{
    // (snip)
    private:
        ofxHttpUtils httpUtils;
};