基于数据库的安卓 java搜索引擎
请帮助大家，这是我们的论文，我想有一个搜索引擎，将其变量输入数据库
以下是我们的代码：
所有的书。xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:安卓="http://schemas.安卓.com/apk/res/安卓"
安卓:layout_width="fill_parent"
安卓:layout_height="fill_parent"
安卓:orientation="vertical"
>
<!-- Main ListView
Always give id value as list(@安卓:id/list)
-->
<ListView
安卓:id="@安卓:id/list"
安卓:layout_width="fill_parent"
安卓:layout_height="wrap_content"
安卓:background="@drawable/allbooks"
安卓:cacheColorHint="@安卓:color/transparent"/>
</LinearLayout>
java文件和php代码：
所有书籍活动。java
public class AllBooksActivity extends ListActivity {
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> productsList;
// url to get all products list
private static String url_get_all_books = "http://192.168.0.190/安卓_connect/get_all_books.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_ADD_BOOK_RECORDS_COPY = "add_book_records_copy";
private static final String TAG_PID = "pid";
private static final String TAG_TITLE = "title";
// products JSONArray
JSONArray add_book_records_copy = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.all_books);
// Hashmap for ListView
productsList = new ArrayList<HashMap<String, String>>();
// Loading products in Background Thread
new LoadAllBooks().execute();
// Get listview
ListView lv = getListView();
// on seleting single product
// launching Edit Product Screen
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String pid = ((TextView) view.findViewById(R.id.pid)).getText()
.toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(),
EditBooksActivity.class);
// sending pid to next activity
in.putExtra(TAG_PID, pid);
// starting new activity and expecting some response back
startActivityForResult(in, 100);
}
});
}
// Response from Edit Product Activity
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// if result code 100
if (resultCode == 100) {
// if result code 100 is received
// means user edited/deleted product
// reload this screen again
Intent intent = getIntent();
finish();
startActivity(intent);
}
}
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllBooks extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(AllBooksActivity.this);
pDialog.setMessage("Loading books. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All books from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_get_all_books, "GET",
params);
// Check your log cat for JSON reponse
Log.d("All Books: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Books
add_book_records_copy = json
.getJSONArray(TAG_ADD_BOOK_RECORDS_COPY);
// looping through All Books
for (int i = 0; i < add_book_records_copy.length(); i++) {
JSONObject c = add_book_records_copy.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_PID);
String title = c.getString(TAG_TITLE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_PID, id);
map.put(TAG_TITLE, title);
// adding HashList to ArrayList
productsList.add(map);
}
} else {
// no products found
// Launch Add New product Activity
Intent i = new Intent(getApplicationContext(),
NewBooksActivity.class);
// Closing all previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
AllBooksActivity.this, productsList,
R.layout.list_item, new String[] { TAG_PID,
TAG_TITLE }, new int[] { R.id.pid,
R.id.title });
// updating listview
setListAdapter(adapter);
}
});
}
}
}
获取所有书籍。php
<?php
/*
* Following code will list all the products
*/
// array for JSON response
$response = array();
// include db connect class
require_once __DIR__ . '/db_connect.php';
// connecting to db
$db = new DB_CONNECT();
// get all products from products table
$result = mysql_query("SELECT * FROM add_book_records_copy") or die(mysql_error());
// check for empty result
if (mysql_num_rows($result) > 0) {
// looping through all results
// products node
$response["add_book_records_copy"] = array();
while ($row = mysql_fetch_array($result)) {
// temp user array
$add_book_records_copy = array();
$add_book_records_copy["pid"] = $row["pid"];
$add_book_records_copy["title"] = $row["title"];
$add_book_records_copy["authors"] = $row["authors"];
$add_book_records_copy["subject"] = $row["subject"];
$add_book_records_copy["created_at"] = $row["created_at"];
$add_book_records_copy["updated_at"] = $row["updated_at"];
// push single product into final response array
array_push($response["add_book_records_copy"], $add_book_records_copy);
}
// success
$response["success"] = 1;
// echoing JSON response
echo json_encode($response);
} else {
// no products found
$response["success"] = 0;
$response["message"] = "No products found";
// echo no users JSON
echo json_encode($response);
}
?>
db_配置。php
<?php
/*
* All database connection variables
*/
define('DB_USER', "root"); // db user
define('DB_PASSWORD', "admin1"); // db password (mention your db password here)
define('DB_DATABASE', "安卓hive"); // database name
define('DB_SERVER', "192.168.0.164"); // db server
?>
db_连接。php
<?php
/**
* A class file to connect to database
*/
class DB_CONNECT {
// constructor
function __construct() {
// connecting to database
$this->connect();
}
// destructor
function __destruct() {
// closing db connection
$this->close();
}
/**
* Function to connect with database
*/
function connect() {
// import database connection variables
require_once __DIR__ . '/db_config.php';
// Connecting to mysql database
$con = mysql_connect(DB_SERVER, DB_USER, DB_PASSWORD) or die(mysql_error());
// Selecing database
$db = mysql_select_db(DB_DATABASE) or die(mysql_error()) or die(mysql_error());
// returing connection cursor
return $con;
}
/**
* Function to close db connection
*/
function close() {
// closing db connection
mysql_close();
}
}
?>
请尝试推荐一个基于数据库的搜索引擎，如果你知道如何放置它并在其上生成代码的话。提前谢谢
# 1 楼答案
我目前正在写一篇与你类似的论文。本质上是一样的。 文档搜索引擎
我不建议在关系数据库上进行搜索。这是因为它效率不高，会产生太多误报。此外，它不支持上下文短语，而且与数据的结构过于耦合
以下是我目前在论文中使用的方法：
请注意，非关系型数据库将仅包含实际需要搜索的文档（或数据）。其他持久化信息应该在关系数据库中
总之，关系数据库在检索、插入和删除信息方面非常有效，而非关系数据库在搜索信息方面非常有效
请查看以下文本搜索引擎。它们是用Java编写的，但您的语言可能存在包装器：