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)); ng,64(wOY
} .`w[A
for(int i=0;i<nEndPos.length-1;i++) W`^euBr7R>
{ @34Z/%A
nEndPos = nStartPos[i+1]; {B;<R1
} tjONN(K`
nEndPos[nEndPos.length-1] = nFileLength; 3K)12x$.K
} Cu2eMUGt
} Y9}5&#
jVW .=FK
1=U(ZX+u
//启动子线程 5a8[0&hA 2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IZ9L ;"}
for(int i=0;i<nStartPos.length;i++) R\i8O^[
{ s,z$Vt"h*K
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^)i5.o\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :eHD{=
nStartPos,nEndPos,i); He&7(mQ0^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4c})LAwd&
fileSplitterFetch.start(); *:r6E
} ?WVp,vP
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YJ6y]r K2,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v3zd>fDnRp
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Z~X\Z.
nEndPos = " + nFileLength); fRcs@yZnS
// fileSplitterFetch[nPos.length-1].start(); f&=WgITa
FCr^D$_w
-_%8Q#"
//等待子线程结束 v@xbur\L
//int count = 0; `Zdeq.R]
//是否结束while循环 nky%Eb[\
boolean breakWhile = false; Re[x$rw
3bWYRW
B|fh 4FNy
while(!bStop) /5**2Kgv1
{ J&hzr t
write_nPos(); a9f!f %9
Utility.sleep(500); [ GcH4E9r
breakWhile = true; 0fOx&"UAB
^<$$h
/JcfAY
for(int i=0;i<nStartPos.length;i++) ~8oti4
{ 8D H~~by
if(!fileSplitterFetch.bDownOver) Sa8KCWgWh
{ -(oFO'Lbg
breakWhile = false; 6np
break; rT#2'-f
} L- '{
} k vuSE
if(breakWhile) pqT+lai)#
break; >$/<~j]
ce&Q}_
xr*%:TwCta
//count++; 6@rebe!&=
//if(count>4) YK{E=<:
// siteStop(); l-v(~u7
} `] fud{
qj.>4d
g+RgDt9
System.err.println("文件下载结束！"); ^CBc~um2
} 9Z[EzKd<~'
catch(Exception e){e.printStackTrace ();} TA9Kg=_
} 1WP(=7$.
S6d&w6
qOqU CRUe:
//获得文件长度 xj!G9x<!
public long getFileSize() dvc=<!"'S
{ hvFXYq_[O
int nFileLength = -1; ?'8(']/
try{ JmP[9"
URL url = new URL(siteInfoBean.getSSiteURL()); HxAN&g*:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 39yp1
httpConnection.setRequestProperty("User-Agent","NetFox"); 2 -C*RHRx
j@o \d%.'!
@CB&*VoB
int responseCode=httpConnection.getResponseCode(); *+UgrsRk
if(responseCode>=400) ?cB:1?\j
{ <i$ud&D
processErrorCode(responseCode); nOQvBc
return -2; //-2 represent access is error m>:zwz< ;
} SDbR(oV
Ovhd%qV;Y
yQ03&{#
String sHeader; 2uEvu
Lu.C+zgQ
@ L=dcO{r
for(int i=1;;i++) K2o\+t
{ k|r|*|8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /QW-#K|S&
//Utility.log(in.readLine()); xX:N-
sHeader=httpConnection.getHeaderFieldKey(i); q}+Fm?B
if(sHeader!=null) =jWjUkm2
{ 0|chRX
if(sHeader.equals("Content-Length")) dRGgiQO
{ EpCT !e
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %>z)Q
break; /@O$jlX5I
} -tH^Deo
} GF/!@N
else i.5?b/l0
break; +FBUB
} 5*hA6Ex7
} (/[wM>q:r
catch(IOException e){e.printStackTrace ();} 1"fbQ^4`
catch(Exception e){e.printStackTrace ();} T!YfCw.HZ
ls,;ozU
gLzQM3{X9
Utility.log(nFileLength); DQ`\HY
)KbzgmLr
3$n O@rOS
return nFileLength; \\(3gB.Gd
} L3J .Oh
.Gcs/PN
[9H986=
//保存下载信息（文件指针位置） -RBH5+SS2
private void write_nPos() G9AQIU%ii
{ %SC%#_7
try{ %4I13|<A`
output = new DataOutputStream(new FileOutputStream(tmpFile)); GS qt:<Qs
output.writeInt(nStartPos.length); B4RP~^
for(int i=0;i<nStartPos.length;i++) /DxeG'O
{ mIYM+2p
// output.writeLong(nPos); HlgkW&}c^
output.writeLong(fileSplitterFetch.nStartPos); d#cEAy
output.writeLong(fileSplitterFetch.nEndPos); nJr:U2d
} S7kZpD$
output.close(); 1MYA/l$
} `&/~%>
catch(IOException e){e.printStackTrace ();} PCX X[N
catch(Exception e){e.printStackTrace ();} ( SiwO.TZ
} VI(2/**
c W^
!wr2OxK*
//读取保存的下载信息（文件指针位置） H+?@LPV*N
private void read_nPos() ykBq?Vr
{ h/xV;oj
try{ Kn`-5{1B|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 586lN22xM
int nCount = input.readInt(); <E1ngG
nStartPos = new long[nCount]; z$b'y;k
nEndPos = new long[nCount]; )Q)H!yin
for(int i=0;i<nStartPos.length;i++) $guaUe[x
{ yN:U"]glC
nStartPos = input.readLong(); 9^2l<4^Z
nEndPos = input.readLong(); ]MaD7q>+R
} /=+Bc=<lZ
input.close(); ~0T,_N
} $(N+E,XB
catch(IOException e){e.printStackTrace ();} ,cwjieM
catch(Exception e){e.printStackTrace ();} +WfO2V.
} <-s5 ;xwtS
q7aH=dhw
m5kt O^EU
private void processErrorCode(int nErrorCode) GI[XcK^*w
{ /;V:<mekf
System.err.println("Error Code : " + nErrorCode); b6ui&Y8z
} ,4Qct=%L_
:#nv:~2]
PsOu:`=r
//停止文件下载 h%+6y
public void siteStop() O]-s(8Oo3
{ x!;;;iS
bStop = true; %=<Kb\
for(int i=0;i<nStartPos.length;i++) `#y?:s]e
fileSplitterFetch.splitterStop(); Ojs^-R_
[`_-;/Gx2
?a{es!
} 9 6j*F,{
} dW} m44X
//负责部分文件的抓取 tJ9-8ZT*
**FileSplitterFetch.java x>eV$UJ
*/ Nny#}k Bt
package NetFox; =DLVWz/<
cFV3
' "I-! +
import java.io.*; 7CV}QV}G
import java.net.*; S0jYk(
0;n}{26a
p{W'[A{J .
public class FileSplitterFetch extends Thread { g$9EI\a
%Z!3[.%F
Rw]lW;EN<
String sURL; //File URL A#x_>fV
long nStartPos; //File Snippet Start Position 6< @F
long nEndPos; //File Snippet End Position m={TBV,L
int nThreadID; //Thread's ID ~X<Ie9m1x
boolean bDownOver = false; //Downing is over Cs?[
boolean bStop = false; //Stop identical 65>}Q.p
FileAccessI fileAccessI = null; //File Access interface I6.}r2?;A
o@@, }
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4#Id0['
{ 'FN+BvD
this.sURL = sURL; u~\l~v^mj
this.nStartPos = nStart; a~Nh6 x
this.nEndPos = nEnd; ~xakz BE
nThreadID = id; `2PvE4]%p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M#o'hc
} o@W:PmKW
T.GB*
,!Q^"aOT:
public void run() j@C*kj;-
{ b5t:">wC
while(nStartPos < nEndPos && !bStop) ?CO..l
{ D'Y=}I)8Dn
z!>ml3
Rr"D)|Y;C(
try{ :WHbwu,L$
URL url = new URL(sURL); `ZZq Sc4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5sI9GC
httpConnection.setRequestProperty("User-Agent","NetFox"); #{x4s?
String sProperty = "bytes="+nStartPos+"-"; fYUbr"Oe
httpConnection.setRequestProperty("RANGE",sProperty); I`4k5KB;
Utility.log(sProperty); -H9WwFk
u7}C):@H
]m@p? A$
InputStream input = httpConnection.getInputStream(); N)Qz:o0W
//logResponseHead(httpConnection); +p):
!bQqzny$R
-I*NS6
byte[] b = new byte[1024]; Z<W`5sop^
int nRead; o*Kl`3=]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .XPPd?R
{ WR5W0!'Tf
nStartPos += fileAccessI.write(b,0,nRead); }/g1s71
//if(nThreadID == 1) y vo4 .u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~?<VT k
} ^gdv:[m
7?a!x$-U(
bXRSKp[$
Utility.log("Thread " + nThreadID + " is over!"); (bD'SWE
bDownOver = true; vR?E'K3
//nPos = fileAccessI.write (b,0,nRead); SnFAv7_
} Kl]LnN%A{
catch(Exception e){e.printStackTrace ();} i8i~b8r]
} O~&j}WN
} _ Y8jl,J
`VD7VX,rp*
l$DQkbOj
//打印回应的头信息 R~H+.Vh
public void logResponseHead(HttpURLConnection con) \Ws$@J-M
{ -$tf`
for(int i=1;;i++) LypBS]ru
{ n2;Vrs,<1&
String header=con.getHeaderFieldKey(i); B(qwTz 51
if(header!=null) yYn7y1B
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %w#8t#[,6
Utility.log(header+" : "+con.getHeaderField(header)); h[}e5A]}
else 8s)(e9Sr
break; t>%+[7?6
} xay~fD
} X}G3>HcP
,<O|Iis
K~Z$NS^W&
public void splitterStop() ;b;Bl:%?
{ Zil<*(kv{
bStop = true; vd#BT$d?
} `|f1^C^
:<i<\TH'
}-2U,Xg[
} [s&0O<Wv
k btQ
>@?`n}r|
/* B'!I{LC
**FileAccess.java gib'f@i;
*//文件访问(定位，写) S/)yi
package NetFox; /{FSG!
import java.io.*; 35Cm>X
Be~In~~
4StoEgFS
public class FileAccessI implements Serializable{ ;$/]6@bqB
mWX{I2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 qz&?zzz;
RandomAccessFile oSavedFile; u?lbC9}$
long nPos; hL}AgY@
z\+Ug9Of
(;cvLop
public FileAccessI() throws IOException U]64HuL
{ h$$2(!G4
this("",0); H rI(uZ]
} lCiRvh1K
e(Y5OTus
a}5/?/
public FileAccessI(String sName,long nPos) throws IOException Pm==m9
{ zp:EssO=Q
oSavedFile = new RandomAccessFile(sName,"rw"); <(W:Q3?s
this.nPos = nPos; NEff`mwm5)
oSavedFile.seek(nPos); X^7n/|%*.
} 3eR c>^wh
0^mCj<g
-E>LB\[t)
public synchronized int write(byte[] b,int nStart,int nLen) `tH:oP0=
{ A!IZIT5)m
int n = -1; E5 uk<e_
try{ <P0&!yN
oSavedFile.write(b,nStart,nLen); ?eOw8Rom
n = nLen; Fb<fQIa
} gRg8D{
catch(IOException e) Q1[EiM3
{ "`Y.5.
e.printStackTrace (); Y?xc#'
} $n_ax\15
AGK{t+`
Z:.*fs5
return n; Bnh*;J0
} ]!v\whZ>
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d~z%kl 5:
} kadw1sYj
-$ha@bCWO
)| 0(#R
/* 21 N!?DR
**SiteInfoBean.java \JBPZ~N3
*/ ~%QI#s?|
package NetFox; OTD<3Q q
#y*p7~|@
5m9;'SF
public class SiteInfoBean { 3h**y %^
g-DFcwO,V
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private String sSiteURL; //Site's URL 2}U:6w
private String sFilePath; //Saved File's Path UX@8
private String sFileName; //Saved File's Name FC#t}4as
private int nSplitter; //Count of Splited Downloading File sPRo=LB
e7M6|6nb
F`M`c%
public SiteInfoBean() =PIarUJ
{//nSplitter的缺省值为5 g [c^7
//default value of nSplitter is 5 {"mb)zr
this("","","",5); wPl9%
} DMiB \o
Lv7$@|"H9
{)PgN
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .wf$]oQQ
{ =&#t("
sSiteURL= sURL; 5q _n69b
sFilePath = sPath; rFhi:uRV
sFileName = sName; ,d7o/8u
this.nSplitter = nSpiltter; #r'S@:[
2k+u_tj>
j W/*-:
} A@)ou0[n@
[ ]42$5eof
l^R1XBP
public String getSSiteURL() Mu/hTTiNx
{ oD=+
return sSiteURL; lD6PKZ\RIj
} StU9r0`
epG!V#I
BQL](Y"
public void setSSiteURL(String value) \T {<{<n
{ ca,U>'(y
sSiteURL = value; S3gd'Bahq
} 1;JH0~403
jS4fANG
J=Hyoz+9
public String getSFilePath() t(Gg 1
{ n..R'vNj
return sFilePath; !'*1;OQ
} {!xDJnF;
`gz/?q
_:+ k|I
public void setSFilePath(String value) lf}%^od~6
{ FQM9>l@6)>
sFilePath = value; i Ie{L-Na
} "z4V@gk
'wVi>{?
}ZJ*N Y
public String getSFileName() A>%mJ3M
{ \?"p]&2UcB
return sFileName; qKk|2ecTB5
} |'](zEwq
MS;^@>|wj
F?XiP.`DR
public void setSFileName(String value) U:uFrb,
{ a]@BS6
sFileName = value; fr<V])
} F.-:4m(Z
^1;Eq>u
A$-\Er+f
public int getNSplitter() 3c[]P2Bh
{ ,D2nUk
return nSplitter; +lZvj=gW
} b)7v-1N
K[l5=)G0L
MY l9 &8
public void setNSplitter(int nCount) mT,#"k8
{ t(p}0}Pp
nSplitter = nCount; V z-]H]MW,
} [}`-KpV!;
} Dr5AJ`y9A
>\[|c
PLRMW2
/* }-~LXL%!3
**Utility.java naVbcY
*/ a LJ d1Q
package NetFox; Ww=b{lUD
<jG[ z69)
["sm7yQ
public class Utility { CvRO'
q``:[Sz
*+_+ZDU
public Utility() hkx(r5o
{ ._TN;tR~'
L u1pxL
W{fNZb'
} 5=/j
Fil6;R
//线程睡眠 nhRpb9f`1@
public static void sleep(int nSecond) Kiq[PK
{ *vOk21z77d
try{ Fhga^.5U&
Thread.sleep(nSecond); czT]XF
} ]nq/yAF%
catch(Exception e) :ka^ztXG
{ =Y5_@}\0
e.printStackTrace (); qK]Om6 a~
} W~/{ct$Y
} k,-0OoCL-!
Zu/w>
//日志 qO[_8's8
public static void log(String sMsg) vGwpDu\RgX
{ +P<#6<gR
System.err.println(sMsg); 8~AL+*hn
} ! =*k+gpF
:M8y 2fh
{43J'WsJ
public static void log(int sMsg) VcLzv{
{ \i3)/sZ?l
System.err.println(sMsg); A=r8_.@2@
} ;cGY
} >1$Vh=\OI
'cA(-ghY/E
.JV y}^Q\
/* Rd[^)q4d$w
**TestMethod.java Y(=A HmR
*/ w%-S5#
package NetFox; h!?rk|
|IDZMd0
r!~6.
public class TestMethod { L| ;WE=
otlv;3263
R#ZO<g%'
public TestMethod() gv,1 CK
{ ///xx/weblogic60b2_win.exe u>/Jb+
try{ +0)H~ qB\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ijgm-1ECk3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l OiZ2_2
SiteFileFetch fileFetch = new SiteFileFetch(bean); r?/!VO-*N
fileFetch.start(); KBa0
} d;i@9+
catch(Exception e){e.printStackTrace ();} & l0LW,Bx
$hy0U_}6
Q9i[?=F:z
} _gw paAJ
Qh+zs^-?
i5gNk)D
public static void main(String[] args) Z1{>"o:@
{ o{3>n"\w3
new TestMethod(); 0wt4C% .0
} ~-#Jcw$+n=
} 9-!GYa'Z
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