http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); l[.*X
} >&f .^p
for(int i=0;i<nEndPos.length-1;i++) :CV!:sUm
{ T?I&n[Y|
nEndPos = nStartPos[i+1]; 36s[hg
} pv~XZ(J.1
nEndPos[nEndPos.length-1] = nFileLength; c (O+s/
} 7]_UZ)u
} Ro*$7j0!Hf
4tz8^z[Kw
kzZtKN9Az
//启动子线程 C0[Rf.*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^)m]j`}IGb
for(int i=0;i<nStartPos.length;i++) @#c(4}^ <w
{ f#pT6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w;vp X>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =iC5um:
nStartPos,nEndPos,i); r*C:)z.}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q*+@"tk<
fileSplitterFetch.start(); E j@M\
} s1<_=sfnT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y%Ui)UMnw]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B08q/qi
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f&bY=$iff
nEndPos = " + nFileLength); [Qa0uM#SU
// fileSplitterFetch[nPos.length-1].start(); s[)2z3
%L+/GtxK
;Z:z'';Lm
//等待子线程结束 ;TD<\1HJT=
//int count = 0; >V;JI;[
//是否结束while循环 XtRfzqg?K
boolean breakWhile = false; 12])``9
X&0m$x
CsS0(n(x
while(!bStop) 0I* ^VGZ
{ Z`v6DfK}
write_nPos(); O66\s q
Utility.sleep(500); u`$,S&Er
breakWhile = true; %?J\P@
2/RK pl &
e<dFvMO
for(int i=0;i<nStartPos.length;i++) dt{|bQLu3
{ <~!7?ak
if(!fileSplitterFetch.bDownOver) Pk T&zSQA
{ W%hdS<b
breakWhile = false; i)Vqvb0Q
break; b{)9?%_
} Hq8<g$
} J\b,rOIf
if(breakWhile) \/$T 3f`x
break; ptQr8[FA
#!u P>/
G5egyP;
//count++; BoG/Hd.S
//if(count>4) Mcj4GjV6:"
// siteStop(); TD].*9
} JXUnhjB,B
B3@
d*khda;Vj
System.err.println("文件下载结束！"); z[b,:G
} %+|k>?&z7
catch(Exception e){e.printStackTrace ();} fu}NH\{
} aCcBmc
S&}7jRH1
EShc1KPqc
//获得文件长度 *E+2E^B
public long getFileSize() }OJ*o
{ `sQ\j Nu
int nFileLength = -1; - y{*U1[
try{ >~_y\
URL url = new URL(siteInfoBean.getSSiteURL()); 9G` 2t~%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "zc@(OA[z
httpConnection.setRequestProperty("User-Agent","NetFox"); $TU=^W)X
d?GfT$1
!p >a,8w
int responseCode=httpConnection.getResponseCode(); nS"K dPM
if(responseCode>=400) o<1e-
{ GBzC<e#
processErrorCode(responseCode); s+(%N8B
return -2; //-2 represent access is error TDBWYppM
} BWFl8 !_X
/p~"?9b[ i
D{Y~kV|
String sHeader; w5gN8ZF3
A9qCaq{
^+oi|y
for(int i=1;;i++) vC E$)z'"
{ m~1{~'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); TC?kuQI
//Utility.log(in.readLine()); ?{?mAbc
sHeader=httpConnection.getHeaderFieldKey(i); 7'S/hV%
if(sHeader!=null) R[LVx-e7'
{ w(8q qU+\
if(sHeader.equals("Content-Length")) 1>jG*tr
{ `I,A7b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O*d&H;;
break; wXPNfV<(2
} FXV=D_G}
} #x1AZwC
else q -M&f@Il
break; >"jV8%!sM
} /*`BGNkYY
} ~"\sL;B
catch(IOException e){e.printStackTrace ();} Ziuf<X{
catch(Exception e){e.printStackTrace ();} nQdNXv<(
k(C?6Gfj
'!Ps4ZTn_
Utility.log(nFileLength); T~cq=i|O
$^ (q0zR~l
>hoIJZP,
return nFileLength; X_C9Z
} ;_amgRP7$
TP{lt6wws(
a3?Dtoy'
//保存下载信息（文件指针位置） -b~MQ/,2
private void write_nPos() ih.UzPg
{ </t_<I0{
try{ 1iS9f~
output = new DataOutputStream(new FileOutputStream(tmpFile)); `]\4yTd
output.writeInt(nStartPos.length); 'G>Ejh@t
for(int i=0;i<nStartPos.length;i++) 7U:,:=
{ 2_vE
// output.writeLong(nPos); BnvUPDT&
output.writeLong(fileSplitterFetch.nStartPos); VD/Wl2DK
output.writeLong(fileSplitterFetch.nEndPos); 96]lI3c
} WLiY:X(+|
output.close(); r/HKxXT
} s#`%c({U|
catch(IOException e){e.printStackTrace ();} SW(7!`
catch(Exception e){e.printStackTrace ();} {.bLh0
} aQCbRS6
vY *p][$
r=n|MT^O
//读取保存的下载信息（文件指针位置） :>nk63V (
private void read_nPos() ioi0^aM
{ VxjEKc
try{ Fly@"W4a
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); '&Q_5\Tn
int nCount = input.readInt(); g,Kb9['
nStartPos = new long[nCount]; _Jk-nZgn
nEndPos = new long[nCount]; SOb17:o3|
for(int i=0;i<nStartPos.length;i++) $JqdI/s
{ ~53E)ilB
nStartPos = input.readLong(); [T"oqO4%]
nEndPos = input.readLong(); ^8.R 'Yq
} Tr)a6Cf
input.close(); l"}W $3]u$
} z~4L=tA(
catch(IOException e){e.printStackTrace ();} ^c< <I-o|
catch(Exception e){e.printStackTrace ();} ?Ee?Ol?i2
} }E]`ly<Z
aBr%"&Z.MG
c[!e*n!y
private void processErrorCode(int nErrorCode) Ptzha?}OZ
{ DG8$zl5
System.err.println("Error Code : " + nErrorCode); {5.,gb@6
} *`ehI_v :
V J){@
n]ar\f
//停止文件下载 d`StBXG!
public void siteStop() R"5/
{ ~Cks)mJs
bStop = true; / Zz2=gDY
for(int i=0;i<nStartPos.length;i++) qzE/n
fileSplitterFetch.splitterStop(); QoDWR5*^D
a: iIfdd4'
hOfd<k\A
} +hY/4Tx<
} gwThhwR
//负责部分文件的抓取 U'";
**FileSplitterFetch.java 6TfL|W<
*/ jt"p Js'
package NetFox; eWqJ2Tt
9Lk.\.
EM vV
import java.io.*; LAwX9q`
import java.net.*; uWx/V+w
PHfGl
;Bcf~[ErM
public class FileSplitterFetch extends Thread { (z2)<_bXJ
PfnhE>[>cf
LN?T$H
String sURL; //File URL !aa^kcEjnL
long nStartPos; //File Snippet Start Position q*DR~Ov
long nEndPos; //File Snippet End Position i.cSD%*
int nThreadID; //Thread's ID uFSgjWJ#~
boolean bDownOver = false; //Downing is over %!(6vm>8
boolean bStop = false; //Stop identical ]!YzbvoR
FileAccessI fileAccessI = null; //File Access interface <2A4}+p:
W}Nd3
2r?g|< :
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q5lRc=.b[
{ =_%:9FnQ0
this.sURL = sURL; wIxLr{
this.nStartPos = nStart; K_]LK
this.nEndPos = nEnd; t@}<&{zk
nThreadID = id; ~rpYZLH/:0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 XZd !c Ff
} F!pUfF,&
F__DPEAc_
WHbvb3'
public void run() ?aSL'GI
{ 3WPMS/
while(nStartPos < nEndPos && !bStop) VxjHB?)
{ &9o @x]) @
AKa{C f
"kP.Kx!
try{ L2{tof
URL url = new URL(sURL); GgA =EdJn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M*t@Q|$:
httpConnection.setRequestProperty("User-Agent","NetFox"); E'XFn'
String sProperty = "bytes="+nStartPos+"-"; e{=7,DRH<
httpConnection.setRequestProperty("RANGE",sProperty); &JfyXM[]
Utility.log(sProperty); mWmDH74
^Xa-)Pu
9!2KpuWji
InputStream input = httpConnection.getInputStream(); r}f-.Fo
//logResponseHead(httpConnection); 7dPA>5"XD
%=#&\ldPS
(~}l?k
byte[] b = new byte[1024]; ]YevO(
int nRead; rZJp>Q)s
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G9E?
{ g^B6NF
nStartPos += fileAccessI.write(b,0,nRead); N_C\L2
//if(nThreadID == 1) \hi{r@k>}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p@cPm8L3
} M_9|YjwS
_ esFx
aMv
Utility.log("Thread " + nThreadID + " is over!"); sB7DF<91
bDownOver = true; D3XQ>T[*q
//nPos = fileAccessI.write (b,0,nRead); -.^Mt.)
} %NeKDE
catch(Exception e){e.printStackTrace ();} jy&p_v1
} Fi7pq2
} ,{'~J @
^4s#nf:}
?[XH`c,
//打印回应的头信息 zw5EaY
public void logResponseHead(HttpURLConnection con) vf5[x!4
{ Em4TEv
for(int i=1;;i++) {\]SvoJnJ
{ mT!~;]RrF
String header=con.getHeaderFieldKey(i); F>^k<E?,C
if(header!=null) w?Q@"^IL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); IDLA-Vxo
Utility.log(header+" : "+con.getHeaderField(header)); s)]|zu0"Ku
else OmU.9PDg-
break; ;yHA.}
} s?0r\cc|:
} QQC0uta`
.Z/"L@
"G`)x+<~Z8
public void splitterStop() vtL)
{ )}paQmy#
bStop = true; y99G3t
} i&_sbQ^
l8^^ O
X^aujK^@
} RCxqqUS\C
bZ3CJ f&mE
|$1j;#h
/* #wC4$y<>
**FileAccess.java H2k>E}`
*//文件访问(定位，写) !_x-aro3<
package NetFox; xss D2*l
import java.io.*; apw8wL2
j5$Sm
q=96Ci_a
public class FileAccessI implements Serializable{ C}+(L3Z
jriliEz;f
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 j4G,Z4
RandomAccessFile oSavedFile; Q%t8cJL
long nPos; &,e@pvc3
/jS
Cs*u{O
public FileAccessI() throws IOException {BKI8vy
{ n'M}6XUw
this("",0); :+[q`
} 9KAXc(-
^[qmELW#7
OM,uR3,
public FileAccessI(String sName,long nPos) throws IOException p=Vm{i7
{ eRv3ZHH
oSavedFile = new RandomAccessFile(sName,"rw"); s\kkD*
this.nPos = nPos; -Tz/ZOJ
oSavedFile.seek(nPos); :T'"%_d5
} Rl6E
.^Ek1fi.
nnr(\r~
public synchronized int write(byte[] b,int nStart,int nLen) Qz/=+A/4
{ )9@Ftzg|
int n = -1; uV%7|/fD
try{ m _:ib}
oSavedFile.write(b,nStart,nLen); D$ `yxc
n = nLen; M4')gG;
} 1}V_:~7
catch(IOException e) #]:nQ(
{ 4'X^YBm
e.printStackTrace (); fmloh1{4
} }|A%2!Q}
#kV=;(lq
%Xp}d5-
return n; F!SmCE(0x
} ,T1t`
eqjl$QWPJS
r!#a.
} L4Kkbt<x
eOLS
nk6xavQji
/* r[~Km5
**SiteInfoBean.java vT[%*)`
*/ D+"5R5J",
package NetFox; /4=O^;
e'7!aysj
#M8"b]oh6
public class SiteInfoBean { >B~p[wh0
vsES`
C\EV$U,
private String sSiteURL; //Site's URL QEtZ]p1H@
private String sFilePath; //Saved File's Path ea7v:#O[S
private String sFileName; //Saved File's Name BH%eu 7`t
private int nSplitter; //Count of Splited Downloading File tR2IjvmsX
lm@<i4%$F
^#"!uCq]gM
public SiteInfoBean() oOJN?97!k
{//nSplitter的缺省值为5 E#_}y}7JY
//default value of nSplitter is 5 m2VF}% EIr
this("","","",5); ~":?})
} "-^TA_XfI
S W
4$vya+mAk5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L!/USh:IP
{ qW7S<ouh
sSiteURL= sURL; Pk*EnA)
sFilePath = sPath; 5z#>>|1>#
sFileName = sName; -*tP_=-Dg
this.nSplitter = nSpiltter; J^1w& 40
9Y*6AaKE6
mDj:w#q
} dr:)+R
V&NOp
^$yr-p%-
public String getSSiteURL() [l'~>
{ PsLuyGR.<
return sSiteURL; 7eh}Je8
} AA yzT*^
UyIjM;X
JNk ]$ xz
public void setSSiteURL(String value) Az"3f
{ r#^X]
sSiteURL = value; [}d 3u!
} I_Oa<J\+
3LX<&."z
ly6?jVJ
public String getSFilePath() b~v
{ Q{mls
return sFilePath; f'R^MX2
} ~@L$}Eu
PZH]9[H
[)9bR1wh
public void setSFilePath(String value) Dth<hS,2J
{ b6oPnP_3P
sFilePath = value; {v~&.|
} 8ae]tX5$
}%_x T
?u 9) GJO[
public String getSFileName() t</Kel|D
{ ;>|:I(l;
return sFileName; 9k2HP]8=[{
} E jBEZL|_
E%jOJA
g24)GjDi
public void setSFileName(String value) I@ }:} 8t
{ D='/-3f!F]
sFileName = value; $5cLhi"`
} 9 `J`(
=^=9z'u"=
g"xLS}Al
public int getNSplitter() JTl 37j
{ {EZ ;
return nSplitter; 1 dI
} -twIF49
QTK\"
OsvAm'B
public void setNSplitter(int nCount) HIi"zo=V
{ 5K{(V^88F
nSplitter = nCount; %^gT.DsX-
} %+FM$xyJ
} =@V4V} ?
~SP.&>Q>
t3v*P6
/* 0O"GI33Mg
**Utility.java c3i|q@ k
*/ e+4p__TmZ
package NetFox; ^/mQo`[G
9?bfZF4A=
BalOph4M[
public class Utility { ?i)-K?4Sb
BxO2w1G
u\&oiwSIP
public Utility() n4(w?,w}
{ ANp4yy+
W[j =!o
9j$ OU@N 8
} <`*6;j.&
u=#LY$
//线程睡眠 (= uwx#
public static void sleep(int nSecond) ?GB($D=Y'&
{ cV)fe`Gg
try{ ,t61IU3"
Thread.sleep(nSecond); t*e+[
} +5?sYp\
catch(Exception e) j\!zz
{ :14O=C
e.printStackTrace (); c{rX7+bN
} zO9|s}J8q
} Z]uN9c
l yO_rZT
//日志 $vlgiJ&f
public static void log(String sMsg) u%VO'}Gz
{ f![x7D$
System.err.println(sMsg); k[y{&f,
} c@5fiRPv!
REnRpp$
^X"G~#v=q
public static void log(int sMsg) |C7GI[P
{ X\X
System.err.println(sMsg); =n9adq
} T*-*U/
} @\u)k
%jKR\f G
@Eqc&v!O
/* <s]K~ Vo
**TestMethod.java ,^:Zf|V
*/ Xdq2.:\
package NetFox; T1\Xz-1
}_@cqx:n^
6:ZqS~-
public class TestMethod { #}:VZ2Z
"g>uNtt~
( F0.lDZ
public TestMethod() XrFyN(p
{ ///xx/weblogic60b2_win.exe XuoI19V[
try{ `lN1u'(:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ud`V"X
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :4]&R9J>o
SiteFileFetch fileFetch = new SiteFileFetch(bean); xm/v:hl=
fileFetch.start(); }@SZ!-t%rD
} ~k|~Q\
catch(Exception e){e.printStackTrace ();} dH#S69>
=qCVy:RL4
(U/6~r'.L
} ;9=9D{-4+
)&se/x+
QRgWzaI
public static void main(String[] args) C&zgt :q6}
{ z})H$]:$
new TestMethod(); 1g2%f9G
} j)'V_@
} %q2dpzNW
点击下载更多相关资料