http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); dUtxG ~9
} &X +Qi
for(int i=0;i<nEndPos.length-1;i++) @+VvZc2Y
{ _M+'30
nEndPos = nStartPos[i+1]; x=yU }lsV
} \fphM6([RK
nEndPos[nEndPos.length-1] = nFileLength; \#[W8k<Z
} oAX-Sg-/$
} ';x .ry
9x,Aqr$t
"3{xa;c
//启动子线程 ~pn9x;N%H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6u3DxFiTm
for(int i=0;i<nStartPos.length;i++) xa`&/W>
{ eB78z@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @.gT&Hq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _F^k>Lq&d
nStartPos,nEndPos,i); _7YAF,@vT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C|Bk'<MI
fileSplitterFetch.start(); zYdSg<[^
} ~F*pV*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sB_o HUMH6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); F_!6C-z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n37C"qJ/i
nEndPos = " + nFileLength); QeA)@x.p
// fileSplitterFetch[nPos.length-1].start(); K6kPNi
i+yqsYKO
:b;2iBVB
//等待子线程结束 YNbs*i&
//int count = 0; O+1e
//是否结束while循环 =y8HOT}8
boolean breakWhile = false; ^>uzMR!q5
+15j^ Az
}$V]00 X
while(!bStop) 5j`"@C5;O
{ l/yLSGjM
write_nPos(); k0?4vA
Utility.sleep(500); _Kx /z
breakWhile = true; L1`^~m|
0/<}.Z]
?L#C'Lz2+
for(int i=0;i<nStartPos.length;i++) cD8.rRyD
{ Q{!lLka
if(!fileSplitterFetch.bDownOver) %}P^B^O
{ MQ2gzKw>
breakWhile = false; ={b/s31H:
break; y-}lz#N
} 2GcQh]ohc
} YL&$cT]1
if(breakWhile) it\{#rb=4
break; bvn?wK
E$/`7p8)
V;?_l?_
//count++; KO<fN,DR
//if(count>4) g?UG6mFbE
// siteStop(); 5Ga>qIM
} ^LTLyt)/
3mZX@h@
O{&5/xBA
System.err.println("文件下载结束！"); JiP]FJ;
} &qFdP'E;$
catch(Exception e){e.printStackTrace ();} $I-$X?
} ExI?UGT
3j0/&ON
JGf6*D"O
//获得文件长度 &529.>
public long getFileSize() VZF/2d84&w
{ *D F5sY
int nFileLength = -1; e}f!zA
try{ eg)=^b
URL url = new URL(siteInfoBean.getSSiteURL()); }_0?S0<#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 79uL"N;
httpConnection.setRequestProperty("User-Agent","NetFox"); hT^6Ifm
n<\^&_a
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int responseCode=httpConnection.getResponseCode(); W<yh{u&,
if(responseCode>=400) x 3#1
{ KwWqsuju
processErrorCode(responseCode); TxwZA
return -2; //-2 represent access is error ~MyP4x/
} /J3e[?78u
X.,SXNS+B
5bv(J T
String sHeader; XYWGX;.=
jN 5Hku[?
tHXt*tzq
for(int i=1;;i++) V8NNIS
{ Vfp{7I$#6"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u7fae$:&
//Utility.log(in.readLine()); y .S0^
sHeader=httpConnection.getHeaderFieldKey(i); nq8mzI
if(sHeader!=null) "Z }'u2%\m
{ l+bP48
if(sHeader.equals("Content-Length")) ,\[&%ph
{ 4eYj.=I
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "f~S3?^!2
break; TuBg4\V
} HV&N(;@
} &B#HgWud
else `BMg\2Ud*
break; @8|- C
} 9Z6] ];8E
} rYeFYPS
catch(IOException e){e.printStackTrace ();} rcq(p(!
catch(Exception e){e.printStackTrace ();} g$?B!!qT
f'aUo|^?
"2 ma]Ps
Utility.log(nFileLength); !V Zl<|
:Py/d6KK
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return nFileLength; Z5[ t/
} hBz~FB];&
%&4sHDP
Q)C#)|S
//保存下载信息（文件指针位置） .gv J;A7
private void write_nPos() ov#/v\|0
{ 4cr >sz
try{ XkCbdb
output = new DataOutputStream(new FileOutputStream(tmpFile)); P00d#6hPJ
output.writeInt(nStartPos.length); tu6c!o,@
for(int i=0;i<nStartPos.length;i++) z++*,2F
{ 8 ]dhNA5
// output.writeLong(nPos); &y mfA{s
output.writeLong(fileSplitterFetch.nStartPos); t}qoIxy)
output.writeLong(fileSplitterFetch.nEndPos); Io5-[d
} aoco'BR F
output.close(); _z)G!_7.>\
} JnmJN1@I
catch(IOException e){e.printStackTrace ();} !?Z}b.%W
catch(Exception e){e.printStackTrace ();} ,78QLh9:
} my[)/'
+T [0r
5X|=qZ
//读取保存的下载信息（文件指针位置） ^lB1- ;ng
private void read_nPos() /o.wCy,J<
{ E[Tz%x=P
try{ HpSgGhL'J&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); G!8O*4+A
int nCount = input.readInt(); IpoZ6DB$
nStartPos = new long[nCount]; WsL*P.J
nEndPos = new long[nCount]; d&wg\"E
for(int i=0;i<nStartPos.length;i++) O=MO M
{ MQD UJ^I$
nStartPos = input.readLong(); >VE,/?71@
nEndPos = input.readLong(); L<J';#BD
} %TPnC'2
input.close(); Zu_m$Mx
} Dvo.yn|kB
catch(IOException e){e.printStackTrace ();} W~POS'1
catch(Exception e){e.printStackTrace ();} 1V+a;-?
} a_L&*%;
)|XmF4R
?c+_}ja,
private void processErrorCode(int nErrorCode) J1 a/U@"
{ lHV bn7
System.err.println("Error Code : " + nErrorCode); vy,ER<
} FaPX[{_E
Jq l#z/z
0 4x[@f`
//停止文件下载 C^aP)& qt
public void siteStop() Cl6y:21]K
{ 1[[` ^v
bStop = true; AJiEyAC!)5
for(int i=0;i<nStartPos.length;i++) $iEM$
fileSplitterFetch.splitterStop(); 62PtR`b>
DCPK1ql
S3MMyS8
} G{knO?BK
} KY!
//负责部分文件的抓取 sI@m"A
**FileSplitterFetch.java Ib*l{cxN
*/ s!9.o_k
package NetFox; 5MQD:K2
!\}Dxt
U!XC-RA3 _
import java.io.*; SWz+.W{KQ"
import java.net.*; e/r41
UkG|5P`
bVQLj}%
public class FileSplitterFetch extends Thread { q+19EJ(
[~W"$sT
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String sURL; //File URL {<\nl#}5S
long nStartPos; //File Snippet Start Position R^1sbmwk
long nEndPos; //File Snippet End Position y{uRh>l
int nThreadID; //Thread's ID Z WL/AC
boolean bDownOver = false; //Downing is over -=&r}/&
boolean bStop = false; //Stop identical js^@tgf$x&
FileAccessI fileAccessI = null; //File Access interface G':mc{{
^e"BY(
IU{~{(p"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T@U_;v|rf
{ x4CrWm
this.sURL = sURL; J*-m!0 5
this.nStartPos = nStart; 38L8AJqD
this.nEndPos = nEnd; o*_[3{FU
nThreadID = id; ^W eE%"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W|NzdxCY
} X)e6Y{vO
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6;dQ#wmg
public void run() $LRvPan`
{ s_hf,QH
while(nStartPos < nEndPos && !bStop) 0F8y8s
{ V9`VFO
kUUN2
E b-?wzh
try{ MG*#-<OV.
URL url = new URL(sURL); ^+F@KXnL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); we4e>)
httpConnection.setRequestProperty("User-Agent","NetFox"); 8Focs p2
String sProperty = "bytes="+nStartPos+"-"; TbXp%O:[W
httpConnection.setRequestProperty("RANGE",sProperty); )TP1i
Utility.log(sProperty); -;a}'1HOE
[<}:b>a
x>A(016:C
InputStream input = httpConnection.getInputStream(); AY5%<CWj8
//logResponseHead(httpConnection); .5p"o-:D
MH.,dB&
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byte[] b = new byte[1024]; 7Y&W^]UZ0t
int nRead; Y#{ L}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T\:Vu{|
{ rZLTai}`>
nStartPos += fileAccessI.write(b,0,nRead); Y/2@PzA|
//if(nThreadID == 1) +XLy Pj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w,SOvbAxX2
} J/>Y mi,
jmxjiJKP
(@B gsY
Utility.log("Thread " + nThreadID + " is over!"); :;cKns0OA
bDownOver = true; = 7d{lK
//nPos = fileAccessI.write (b,0,nRead); "a6[FqTs
} ^GQ+,0Yy
catch(Exception e){e.printStackTrace ();} BD&JbH!(
} 3V?JX5X\
} ]{jdar^
1\z5[ _
1.+0=M[h
//打印回应的头信息 3lcd:=
public void logResponseHead(HttpURLConnection con) Z `sM(?m
{ \hai
for(int i=1;;i++) 8~YhT]R=
{ a[Ah
String header=con.getHeaderFieldKey(i); o9(:m
if(header!=null) '`p#%I@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x9bfH1
Utility.log(header+" : "+con.getHeaderField(header)); T?4MFx#
else $ jWe!]ASU
break; 8)\TdtBf9
} *v 1hMk
} \XFF(
+)k%jIi!
=e=sK'NvD
public void splitterStop() 3.Z}2F]
{ .t*MGUg
bStop = true; FloCR=^H
} z$ZG`v>0
~2+J]8@I]
l tE`
} JWoNP/v6
bW\OKI1
(S$ziV
/* rV*9=
**FileAccess.java 8fRk8
*//文件访问(定位，写) Au<NUc 2
package NetFox; u&z5)iU
import java.io.*; 3B8\r}L
]&w8"q
F`IV9qv
public class FileAccessI implements Serializable{ 3qwi)nm
w/BaaF.0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _^]2??V
RandomAccessFile oSavedFile; -7,xjn
long nPos; ;*>Y8^K&Q
{Z%4Pg
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public FileAccessI() throws IOException 2L Kpwz?
{ L}NckL
this("",0); P>n}\"z4
} C +S
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j;}!Yn
public FileAccessI(String sName,long nPos) throws IOException d+[GMIxg
{ MWTzJGRT
oSavedFile = new RandomAccessFile(sName,"rw"); = i9|lU"Va
this.nPos = nPos; (Qq;ySZ#
oSavedFile.seek(nPos); 7%DA0.g
} "I+71Ce
}TE4)vXs
O(q1R#n-}+
public synchronized int write(byte[] b,int nStart,int nLen) i E p{
{ uvC ![j^~
int n = -1; 9jW/"
try{ M9so3L<N0
oSavedFile.write(b,nStart,nLen); $fZVh%
n = nLen; w6FtDl$
} P(AcDG6K
catch(IOException e) vdA3
{ U?BuV
e.printStackTrace (); =E$Hq4I
} Ot,eAiaX
ukNB#2"
0 ~K4vSa
return n; |uL"/cMW7
} :+Ti^FF`w
r0jhIE#
rUgTJx&ds
} ~Y;_vU
"A?&`}%
K6 D3
/* 86+nFk
**SiteInfoBean.java bz$)@gLc
*/ N;N,5rxV
package NetFox; 4FLL*LCNX
(NB\wJg $
G_OLUuK?C
public class SiteInfoBean { mtfEK3?2*
NABVU0}
nz-( 8{ae
private String sSiteURL; //Site's URL @px4[
private String sFilePath; //Saved File's Path wX?<o
private String sFileName; //Saved File's Name &\Kp_AR
private int nSplitter; //Count of Splited Downloading File QxUsdF?p
SA3!a.*c
W<']Q_su
public SiteInfoBean() 6IRzm6d
{//nSplitter的缺省值为5 .zDm{_'
//default value of nSplitter is 5 |Iq#Q3w
this("","","",5); 3"B$M
} ]CLt Km
XNZW J
s,~)5nL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Iq/V[v
{ [OTZ"XQLI
sSiteURL= sURL; U`*L`PM
sFilePath = sPath; .MUoNk!
sFileName = sName; ..u2IdEu
this.nSplitter = nSpiltter; gFBMARxi
7Qoy~=E
a@mMa {
} 3/d`s0O
$K-od3h4=
bIs@CDB
public String getSSiteURL() q,ur[ &<
{ 0xZX%2E
return sSiteURL; zI$24L9*
} ~r%>x
HzuB.B<
83~9Xb=!\
public void setSSiteURL(String value) O\;R (
{ 9pY`_lxa>
sSiteURL = value; @ckOLtxE>
} @)hrj2Jw
RlW7l1h&
A~Uqw8n$\
public String getSFilePath() i7 *cpNPO
{ |~V`Es +j
return sFilePath; '5V#sq;Z
} m`3Mev
g#Doed.30=
Z#Q)a;RA
public void setSFilePath(String value) 6<%W8m\
{ a d,0*(</
sFilePath = value; iD/r8_}
} wfE%` 1
Z{#;my*X|
B%~D`[~?
public String getSFileName() \@%sX24D
{ ~-dL #;
return sFileName; sPKyg
} u=mJI*
Z,x9 {
fa=OeuI
public void setSFileName(String value) 3J{hG(5
{ ~YYg~6}vV
sFileName = value; orU++,S4Pm
} \Gzo^w
F|ib=_)3
ww0m1FzX
public int getNSplitter() ^Ko{#qbl/
{ >mWu+Nn:
return nSplitter; n-%8RV
} =2BB ~\G+
JsA9Xdk`
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public void setNSplitter(int nCount) HJV8P2f8`
{ QqS?-
nSplitter = nCount; "-tTN
} P@RUopu,i
} lMcSe8LBQa
vW\|% @hW,
[u=DAk?8
/* K9BoIHo
**Utility.java TAXl73j_CY
*/ ~582'-=+
package NetFox; KPT@I3P
p]7Gj&a
;4g_~fB
public class Utility { #9Fe,
OP-%t\sj>
/p&)bL
public Utility() @|2}*_3\
{ (ex^=fv
N]p|c3D
<;?&<qMo,P
} aD5G0d?u
X?F$jX|c
//线程睡眠 uy,ySBY
public static void sleep(int nSecond) A{7N#-h_
{ ~6hG"t]:
try{ 5xEk 7g.
Thread.sleep(nSecond); iN}BMd.U
} <_|H]^o
catch(Exception e) bnWKfz5
{ `Al[gG?/!
e.printStackTrace (); .)wj{(>TJ
} 0M?nXHA[
} vGk}r
rLzYkZ
//日志 >QusXD"L>
public static void log(String sMsg) )~](qLSl
{ ^1%gQ@P
System.err.println(sMsg); Q)l]TgvSe
} ^z[-pTY
LX %8a^?;
xYMNyj~
public static void log(int sMsg) JMMsOA_]
{ J{Z-4y
System.err.println(sMsg); zn |=Q$81
} C+WHg-l
} 6$'6x2,
aE_)iE|
u%#s_R
/* IXSCYqoK
**TestMethod.java GMw|@?:{
*/ J-W,^%
package NetFox; P80z@!
n},~2
n9zS'VU
public class TestMethod { \w 6%J77
!(!BW9Zt+
6]|NB&
public TestMethod() tk^1Ga3
{ ///xx/weblogic60b2_win.exe VD\pQ.=
try{ h>Z$ n`T
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |U_48
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); S|A?z)I
SiteFileFetch fileFetch = new SiteFileFetch(bean); %@!Vx
fileFetch.start(); HY]vaA`
} 5k`[a93T
catch(Exception e){e.printStackTrace ();} F_SkS?dB
tVhY=X{N?
OpwZTy}1}
} I +,D,Vg
S?{|qlpy
Sa&~\!0t
public static void main(String[] args) B[ f{Ys
{ B;8YX>r
new TestMethod(); I(8,D[G.m
} 6(4o}Sv
} YbC6&_
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