Note
The BufferedReader reads characters; while the InputStream is a stream of bytes.
The BufferedReader can’t read the InputStream directly; So, we need to use an adapter like InputStreamReader to convert bytes to characters format. For example:
// BufferedReader -> InputStreamReader -> InputStream
BufferedReader br = new BufferedReader(
new InputStreamReader(inputStream, StandardCharsets.UTF_8));1. Reads a file from the resources folder.
This example read a file from the resources folder as InputStream; and we can use BufferedReader + InputStreamReader to read it line by line.
InputStreamToReaderExample.java
package com.favtuts.io.howto;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
public class InputStreamToReaderExample {
public static void main(String[] args) throws IOException {
// loads a file from a resources folder
InputStream is = InputStreamToReaderExample.class
.getClassLoader()
.getResourceAsStream("csv/country.csv");
// BufferedReader -> InputStreamReader -> InputStream
// try-with-resources, auto close
String line;
try (BufferedReader br = new BufferedReader(
new InputStreamReader(is, StandardCharsets.UTF_8)
)) {
// read line by line
while((line = br.readLine()) != null) {
System.out.println(line);
}
}
}
}
2. Send an Http post request to Cloudflare endpoints.
This example uses Apache HttpClient to send a POST request to the Cloudflare endpoints to block an IP address. The return is a JSON string in InputStream, and we can use the same BufferedReader + InputStreamReader to reads the bytes stream.
pom.xml
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.13</version>
</dependency>
CloudFlareBanIP.java
package com.favtuts.io.howto;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.concurrent.TimeUnit;
import org.apache.http.Header;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicHeader;
public class CloudFlareBanIP {
private static final String CF_AUTH_EMAIL = "cf_auth_email" ; //PropertyUtils.getInstance().getValue("cf_auth_email");
private static final String CF_AUTH_TOKEN = "cf_auth_token" ; // PropertyUtils.getInstance().getValue("cf_auth_token");
private static final String JSON_TYPE = "application/json";
private static Header[] HTTP_HEADERS = {
new BasicHeader("X-Auth-Email", CF_AUTH_EMAIL),
new BasicHeader("X-Auth-Key", CF_AUTH_TOKEN),
new BasicHeader("content-type", JSON_TYPE)
};
private HttpClient httpClient = HttpClientBuilder.create()
.setConnectionTimeToLive(10, TimeUnit.SECONDS)
.build();
public HttpClient getHttpclient() {
return httpClient;
}
public String banIp(String ip, String note) throws IOException {
StringBuilder json = new StringBuilder();
json.append("{");
json.append("\"mode\":\"block\",");
json.append("\"configuration\":" + "{\"target\":\"ip\",\"value\":\"" + ip + "\"}" + ",");
json.append("\"notes\":\"" + note + "\"");
json.append("}");
StringBuilder result = new StringBuilder();
HttpPost post = new HttpPost("https://api.cloudflare.com/client/v4/user/firewall/access_rules/rules");
post.setHeaders(HTTP_HEADERS);
post.setEntity(new StringEntity(json.toString()));
// read response from the POST request
try (BufferedReader br = new BufferedReader(
new InputStreamReader(getHttpclient().execute(post).getEntity().getContent())
)) {
String line;
while((line = br.readLine()) != null) {
result.append(line);
}
}
return result.toString();
}
}
Download Source Code
$ git clone https://github.com/favtuts/java-core-tutorials-examples
$ cd java-io/how-to
Convert InputStream to BufferedReader in Java
By mkyong |
Viewed: 10,197 (+135 pv/w)Tags:bufferedreader | bytes to characters | cloudflare | httpclient | inputstream | InputStreamReader | java.io< PreviousNext >
Note
The BufferedReader reads characters; while the InputStream is a stream of bytes.
The BufferedReader can’t read the InputStream directly; So, we need to use an adapter like InputStreamReader to convert bytes to characters format. For example:
// BufferedReader -> InputStreamReader -> InputStream
BufferedReader br = new BufferedReader(
new InputStreamReader(inputStream, StandardCharsets.UTF_8));
1. Reads a file from the resources folder.
This example read a file from the resources folder as InputStream; and we can use BufferedReader + InputStreamReader to read it line by line.InputStreamToReaderExample.java
package com.mkyong.io.howto;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
public class InputStreamToReaderExample {
public static void main(String[] args) throws IOException {
// loads a file from a resources folder
InputStream is = InputStreamToReaderExample.class
.getClassLoader()
.getResourceAsStream("file/abc.txt");
// BufferedReader -> InputStreamReader -> InputStream
// try-with-resources, auto close
String line;
try (BufferedReader br = new BufferedReader(
new InputStreamReader(is, StandardCharsets.UTF_8))) {
// read line by line
while ((line = br.readLine()) != null) {
System.out.println(line);
}
}
}
}
2. Send an Http post request to Cloudflare endpoints.
This example uses Apache HttpClient to send a POST request to the Cloudflare endpoints to block an IP address. The return is a JSON string in InputStream, and we can use the same BufferedReader + InputStreamReader to reads the bytes stream.pom.xml
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.13</version>
</dependency>
CloudFlareBanIP.java
package com.mkyong.security.action;
import com.mkyong.security.util.PropertyUtils;
import org.apache.http.Header;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicHeader;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.concurrent.TimeUnit;
public class CloudFlareBanIP {
private static final String CF_AUTH_EMAIL = PropertyUtils.getInstance().getValue("cf_auth_email");
private static final String CF_AUTH_TOKEN = PropertyUtils.getInstance().getValue("cf_auth_token");
private static final String JSON_TYPE = "application/json";
private static Header[] HTTP_HEADERS = {
new BasicHeader("X-Auth-Email", CF_AUTH_EMAIL),
new BasicHeader("X-Auth-Key", CF_AUTH_TOKEN),
new BasicHeader("content-type", JSON_TYPE)
};
private HttpClient httpClient = HttpClientBuilder.create()
.setConnectionTimeToLive(10, TimeUnit.SECONDS)
.build();
public HttpClient getHttpClient() {
return httpClient;
}
public static void main(String[] args) throws IOException {
CloudFlareBanIP obj = new CloudFlareBanIP();
String response = obj.banIp("52.249.189.81", "bad ip");
System.out.println(response);
}
public String banIp(String ip, String note) throws IOException {
StringBuilder json = new StringBuilder();
json.append("{");
json.append("\"mode\":\"block\",");
json.append("\"configuration\":" + "{\"target\":\"ip\",\"value\":\"" + ip + "\"}" + ",");
json.append("\"notes\":\"" + note + "\"");
json.append("}");
StringBuilder result = new StringBuilder();
HttpPost post = new HttpPost("https://api.cloudflare.com/client/v4/user/firewall/access_rules/rules");
post.setHeaders(HTTP_HEADERS);
post.setEntity(new StringEntity(json.toString()));
// read response from the POST request
try (BufferedReader br = new BufferedReader(
new InputStreamReader(getHttpClient().execute(post).getEntity().getContent()))) {
String line;
while ((line = br.readLine()) != null) {
result.append(line);
}
}
return result.toString();
}
}
Download Source Code
$ git clone https://github.com/favtuts/java-core-tutorials-examples
$ cd java-io/how-to