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)); <)\
} ^p433
for(int i=0;i<nEndPos.length-1;i++) u:f.g?!`"
{ td#B$$[
nEndPos = nStartPos[i+1]; jRP9e
} F"<TV&xf
nEndPos[nEndPos.length-1] = nFileLength; B#T4m]E/
} usR:-1{
} 8=U0\<wT
<,!e*V*U
@Js^=G2
//启动子线程 %`[Oz[V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0qj:v"~Q
for(int i=0;i<nStartPos.length;i++) EBX+fzjQo
{ "NgfdLz
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d/O~"d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #DI%l`B
nStartPos,nEndPos,i); rVE!mi]%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +q/ j
fileSplitterFetch.start(); +I {ZW}rA
} uwcm%N;I"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L:ox$RU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .MzVc42<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *?a rEYc8
nEndPos = " + nFileLength); S}Q/CT?au
// fileSplitterFetch[nPos.length-1].start(); 1@)kNg)*$
#MyR:V*a
s?8vs%(l
//等待子线程结束 %)$^_4.g
//int count = 0; F?wfh7q
//是否结束while循环 t0 1@h_WS
boolean breakWhile = false; G98P<cyD
I0 78[3b
CHeU?NtFps
while(!bStop) n\v;4ly^
{ qW1d;pt
write_nPos(); 5v f?E"\r
Utility.sleep(500); .>Gnb2
breakWhile = true; -_bnGY%,
sO,%Ok1
ETw7/S${
for(int i=0;i<nStartPos.length;i++) $?.0>0,<
{ hmRnr=2N
if(!fileSplitterFetch.bDownOver) /A8ua=Kn
{ WUwH W
breakWhile = false; (h}5*u%h
break; ! z^%$;p
} CWP),]#n
} Ry@QJn I<
if(breakWhile) TSGJ2u5ie%
break; dr|>P*
:2'y=t#
^PnXnH?
//count++; S_E-H.d"
//if(count>4) gn2*'_V~3
// siteStop(); T<hS
} toq/G,N Q
o$*aAgS+
>UUcKq1M:
System.err.println("文件下载结束！"); ZA u=m
} !Ez5@
catch(Exception e){e.printStackTrace ();} 2 L>;M
} V`/E$a1&
w\"~*(M
k<.$7Pl3U
//获得文件长度 zTgY=fuz
public long getFileSize() Fgx{ s%&-
{ {|KFgQ'\
int nFileLength = -1; RcZg/{[{
try{ :]Nn(},
URL url = new URL(siteInfoBean.getSSiteURL()); kLsp0%2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n[vwwY
httpConnection.setRequestProperty("User-Agent","NetFox"); YUzx,Y>k
''bh{ .x
-0QoVGw
int responseCode=httpConnection.getResponseCode(); y*F !k{P
if(responseCode>=400) 04K[U9W3
{ o1kTB&E4B
processErrorCode(responseCode); Wq5}SM
return -2; //-2 represent access is error |/qwR~
} J0ysZ]
;u+k!wn
`"(FWK=8)"
String sHeader; j*.K|77WHj
#r=Jc8J_
GI se|[p
for(int i=1;;i++) -w dbH`2Z"
{ L;7u0Yg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {Jna' eS
//Utility.log(in.readLine()); x%v[(*F#y
sHeader=httpConnection.getHeaderFieldKey(i); %O69A$Q[m
if(sHeader!=null) .+07 Ui]I!
{ 43VBx<"
if(sHeader.equals("Content-Length")) L@5j? N?F
{ (-no`j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {\WRW}iO
break; _o52#Q4
} wit rC>
} 9\zasa
else ,qT^e8E+
break; fN_qJm#:$y
} ] 6X;&=H
} Sx0/Dm
catch(IOException e){e.printStackTrace ();} g@O H,h/
catch(Exception e){e.printStackTrace ();} `SH14A*
? K,d
4St-Q]Y _
Utility.log(nFileLength); b9xvLR8
VnYcqeCm
V0<g$,W=
return nFileLength; ~.<QC<dN
} ]vflx^<?
mDXG~*1
@DNwzdP
//保存下载信息（文件指针位置） bess b>=
private void write_nPos() hm\UqIt
{ q'Nafa&a)
try{ |@1M'
output = new DataOutputStream(new FileOutputStream(tmpFile)); :I{9k~
output.writeInt(nStartPos.length); i'QR-B&Z
for(int i=0;i<nStartPos.length;i++) A>ve|us$
{ s&4&\Aq}x#
// output.writeLong(nPos); :4r{t?ytXw
output.writeLong(fileSplitterFetch.nStartPos); xHD$0eq
output.writeLong(fileSplitterFetch.nEndPos); zIA)se Js
} B'e@RhU;
output.close(); =.qX u+
} \ iA'^69
catch(IOException e){e.printStackTrace ();} y9N6!M|'y
catch(Exception e){e.printStackTrace ();} RW<10:
} l>?f+70
QHr'r/0
c{IL"B6>
//读取保存的下载信息（文件指针位置） wmA TV/
private void read_nPos() drxCjuz"
{ >"+ho
try{ .Y0O.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?iZM.$![
int nCount = input.readInt(); e"%uOuIYX
nStartPos = new long[nCount]; .EReYZO
nEndPos = new long[nCount]; '5b0 K1$"
for(int i=0;i<nStartPos.length;i++) qg/FI#r
{ 2q(gWhcj
nStartPos = input.readLong(); 0CvGpM,
nEndPos = input.readLong(); N4z[=b>
} C+t0Zen
input.close(); *8_Dn}u?Jx
} A0Q`Aqs
catch(IOException e){e.printStackTrace ();} \*&?o51!e
catch(Exception e){e.printStackTrace ();} }d>Xh8:%)
} Vc;g$Xr[
lQiw8qD
C>'G?
private void processErrorCode(int nErrorCode) 3d]~e
{ V7}'g6X
System.err.println("Error Code : " + nErrorCode); A|4om=MO
} `zrg?
k<P`
?PS?_+E\L
//停止文件下载 8AuE:=?,,
public void siteStop() )o~/yB7
{ >tPf.xI|l
bStop = true; IdMwpru(
for(int i=0;i<nStartPos.length;i++) .zl[nx[9"D
fileSplitterFetch.splitterStop(); "G~!J\
pg!MtuC}
sVBr6 !v=
} O$;#GpR
} zc=G4F01
//负责部分文件的抓取 n$XEazUb0N
**FileSplitterFetch.java + kT ]qH
*/ x/CM)!U)
package NetFox; I]i( B+D
_WvVF*Q"k
&tvtL
import java.io.*; l$pz:m]Id
import java.net.*; gKl9Nkd!R
Y#Q!mbp
n?$c"}
public class FileSplitterFetch extends Thread { j{r@>g;3
NA/`LaJ
9Bw#VQ
String sURL; //File URL _Y;tD
long nStartPos; //File Snippet Start Position |&{S ~^$
long nEndPos; //File Snippet End Position wggB^ }~
int nThreadID; //Thread's ID i!}6FBZ
boolean bDownOver = false; //Downing is over qEXN}Pq<
boolean bStop = false; //Stop identical ,mHUo4h1O
FileAccessI fileAccessI = null; //File Access interface m7y[Y
W90!*1
/hu>MZ(\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W>i%sHH6
{ [tof+0Y6
this.sURL = sURL; O=V_7I5
this.nStartPos = nStart; aQ$sn<-l
this.nEndPos = nEnd; &.?E[db"h
nThreadID = id; {pH#zs4Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .l_Nf9=
} C 'MR=/sd
#@OPi6.#!<
(m,H 5
public void run() o ?vGI=
{ ?R#$ c]
while(nStartPos < nEndPos && !bStop) z9[TjTH^}T
{ qE[YZ(/f0&
Uzzm2OS`
P'OvwA
try{ =xIZJ8e
URL url = new URL(sURL); PBb&.<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;j/$%lC
httpConnection.setRequestProperty("User-Agent","NetFox"); eIalcBY
String sProperty = "bytes="+nStartPos+"-"; uOLShNo
httpConnection.setRequestProperty("RANGE",sProperty); }' AY#g
Utility.log(sProperty); W6i{yneW
&H;,,7u
]$Z:^"JS3
InputStream input = httpConnection.getInputStream(); iO5g30l
//logResponseHead(httpConnection); aqI"4v]~b
D?1fY!C:r
$xZ ~bE9
byte[] b = new byte[1024]; B??07j
int nRead; i^%$ydg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (?\+
{ \6&Ml]1
nStartPos += fileAccessI.write(b,0,nRead); tj@(0}pi4
//if(nThreadID == 1) e9KD mX_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )ciP6WzzbI
} rvd$4l^
hOAZvrfQ4
`2s@O>RV
Utility.log("Thread " + nThreadID + " is over!"); 2uE<mjCt-r
bDownOver = true; {s0%XG1$
//nPos = fileAccessI.write (b,0,nRead); P+hcj p*
} bJ!\eI%ld
catch(Exception e){e.printStackTrace ();} Cr7Zi>sd<!
} 1W{N6+u
} . |T=T0^
E:pk'G0bZ
#%p44%W
//打印回应的头信息 MMFwT(l<1
public void logResponseHead(HttpURLConnection con) `]eJF|"
{ {g%N(2
for(int i=1;;i++) AYA{_^#+3
{ M@A3+v%K
String header=con.getHeaderFieldKey(i); ;yt6Yp.6e
if(header!=null) l:V R8g[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %vJHr!x
Utility.log(header+" : "+con.getHeaderField(header)); f)/Z7*Z
else l!|c_
break; NZq-%bE
} _AX9Mu]
} `Y?VQ~ci>
N*-tBz
u-TT;k'
public void splitterStop() BY6#dlDi
{ S:_Ms{S
bStop = true; C$y6^/7)
} 3^o(\=-JX
G68KoM
X1| +9
} \cIN]=#
g<:Lcg"u
X8|H5Y:
/* K~ eak\=
**FileAccess.java y*i&p4Y*
*//文件访问(定位，写) %v0M~J}+
package NetFox; DK4yAR,g
import java.io.*; n$/|r
c?A$Y?|9
OsgPNy0
public class FileAccessI implements Serializable{ @Po5AK3cy
Lzh8-d=HQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]at$ohS
RandomAccessFile oSavedFile; YJJ1N/Z1
long nPos; .a*?Pal@@
E=sh^Q(A
j_8 YFz5
public FileAccessI() throws IOException PF{uaKWk
{ )(}[S:`
this("",0); MpCPY"WLL
} !7N:cx'Qy
>ED;_L*_o
0]DOiA
public FileAccessI(String sName,long nPos) throws IOException kuEXNi1l
{ -c`xeuzK'
oSavedFile = new RandomAccessFile(sName,"rw"); |a(KVo
this.nPos = nPos; `0d0T~
oSavedFile.seek(nPos); BhJ>G%
} O<m46mwM
O=0p}{3l
22l'kvo4"
public synchronized int write(byte[] b,int nStart,int nLen) MP%#)O6
{ }a]`"_i;[
int n = -1; "-4|HA
try{ W5|{A])N
oSavedFile.write(b,nStart,nLen); -KiPqE%&G
n = nLen; ?%O>]s
} V6g*"e/8
catch(IOException e) 2q?/aw ;Z
{ LO`0^r
e.printStackTrace (); X5)D[aE6
} oC&}lp)q
mb\T)rj
i$Y#7^l%k
return n; Jf^3nBZ
} CsR[@&n'
f|> rp[Gk
9{pT)(Wnb
} RoqkT|#$
uLdHE5vr
#qd!_oN
/* }e7Rpgu
**SiteInfoBean.java }&v}S6T
*/ Q2fxsa[
package NetFox; RXXHg
w-).HPe
pMU\f
public class SiteInfoBean { Q& [!+s:2J
1j2U,_-
XpAJP++
private String sSiteURL; //Site's URL Ar%*NxX
private String sFilePath; //Saved File's Path :!i=g+e]
private String sFileName; //Saved File's Name D0J{pAJ
private int nSplitter; //Count of Splited Downloading File 5OdsT-y
r/h\>s+N
AbNr]w&pXC
public SiteInfoBean() 'iMzp]V;
{//nSplitter的缺省值为5 9/"&6,
//default value of nSplitter is 5 BA a:!p
this("","","",5); yzEyOz@Q
} lBP?7`U
a`Bp^(f}
ivo3pibk%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) LJrH_h8C
{ :$I"n\
sSiteURL= sURL; ;(K/O?nrJ
sFilePath = sPath; W=Syo&;F8
sFileName = sName; tGOJ4 =
this.nSplitter = nSpiltter; #X]*kxQ<
6$"IeBRO
8jCho
} w&@tP^`
fBX@ MedC
#8jiz+1 _
public String getSSiteURL() zd_N' :6
{ 8 n[(\f:
return sSiteURL; &zYQH@
} @+;.W>^h
h.-L_!1B7
$.C\H,H
public void setSSiteURL(String value) 9#[,{2pJr
{ uP4yJ/]
sSiteURL = value; (6c/)MH
} Z6B$\Q5Od
W. d',4)
aVr(*s;/
public String getSFilePath() >~d'i
{ 8Z}%,G*n
return sFilePath; [cDkmRV
} t=lDN'\P
Jd `Qa+
'xd8rN%T
public void setSFilePath(String value) L0VZ>!*o
{ jhRr!
sFilePath = value; R|@~<*
} 7cV G?Wr
Z<<=2Xl(
UNSXr`9
public String getSFileName() T5`ML'Dej
{ zWPX
return sFileName; {$t*XTY6R
} z}}P+P/
?9?A)?O<j~
\v+>qY<q
public void setSFileName(String value) eSIG+{;&
{ {oOUIP
sFileName = value; %qsl<_&
} ]Ndy12,M
;4dFL\KU
(z;lNl(*C
public int getNSplitter() ;d>n2
{ Q(A$ >A
return nSplitter; Rkg)yme!N
} 4cy,'B
N,B!D~@
W'Ew!]Q3
public void setNSplitter(int nCount) WnGi;AGH=1
{ a Z)1SX`D
nSplitter = nCount; D9;pjY
} Fnk@)1
} <!G\%C
gT=pO`a
L1+s0g>
/* mVS^HQ:
**Utility.java m<#^c?u
*/ =mX26l`B
package NetFox; \7h>9}wGf
^AI02`c.
ab9ecZ
public class Utility { }oiNgs/N
gREk,4DAv
g-!
public Utility() n(V{ [
{ nVoWER:
}&L%c>
2[=3-1c
} +-),E.
>}+R+''nR
//线程睡眠 N)D+FV29y
public static void sleep(int nSecond) Yj bp:
{ wC%qSy'
try{ 7@g0>1Fz
Thread.sleep(nSecond); I0H]s/*C%9
} `YwJ.E
catch(Exception e) o_b3G
{ IUEpE9_
e.printStackTrace (); /;}%E
} ?%~^PHgZ|
} dR_6j}
Id`V`|q
//日志 6jBi?>[I
public static void log(String sMsg) <[ 2?~s
{ #C.
System.err.println(sMsg); ~4=*kJ#7
} l(87s^_
m44a HBwId
2ry@<88
public static void log(int sMsg) / yBrlf
{ o9sPyY$aQ
System.err.println(sMsg); P%Vq#5
} [[^95:
} $+n6V2^K)7
+'5I8FE-
zdU46|!u
/* _4)z:?G5
**TestMethod.java VZr:yE
*/ Ng!d6]
package NetFox; N8Zz6{rp
OqciZ@#5n
=$)M-;6
public class TestMethod { #z%D d{E
U'9z.2"}9
8 I_
public TestMethod() 4c(Em+4
{ ///xx/weblogic60b2_win.exe N2'aC} I
try{ QM3DB
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Kw?3joy
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -j]k^
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;9h;oB@
fileFetch.start(); J+E,UiZU
} h ':ZF
catch(Exception e){e.printStackTrace ();} (oX!D(OI
rqmb<# Z
0stc$~~v
} V+lF|CZb5
RfTGTz@H
^O+(eA7E
public static void main(String[] args) _7;:*'>a4
{ 1 rhZlmf[r
new TestMethod(); W!? h2[
} nDC0^&
} HVHv,:bPo
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