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)); 5&q@;vR
} jV)!9+H#
for(int i=0;i<nEndPos.length-1;i++) B~oSKM%8R
{ HVaWv].
nEndPos = nStartPos[i+1]; cY?< W/
} T0n=nC}<
nEndPos[nEndPos.length-1] = nFileLength; aCzdYv\}&
} |g]TWKc*
} Q>f^*FyOw<
G%~=hEK0
.kh%66:
//启动子线程 B$qmXA)ze
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )iadu
for(int i=0;i<nStartPos.length;i++) .E:[\H"
{ J,;[n*s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0HK03&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %J4]T35^2
nStartPos,nEndPos,i); MN\/F4Io
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q+2yp&zF
fileSplitterFetch.start(); Kd^{~Wlz&z
} H6?ZE
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J7X-=E D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3nv7Uz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", X.<_TBos|
nEndPos = " + nFileLength); G|FF
// fileSplitterFetch[nPos.length-1].start(); -e7|DXj
|gEA.} pY
+4^XFPq~
//等待子线程结束 ,t5X'sY L
//int count = 0; 3N6U6.Tqb
//是否结束while循环 D3Lu]=G
boolean breakWhile = false; EJY[M
)3v0ex@Jl
UI|L;5
while(!bStop) G3&ES3L
{ Gxfw!aF~
write_nPos(); vco/h
Utility.sleep(500); c/ %5IhX?
breakWhile = true; YfUdpa0
cAC2Xq
|Axg}Q|
for(int i=0;i<nStartPos.length;i++) %Q"zU9
{ ~J!a?]
if(!fileSplitterFetch.bDownOver) H4 Y7p
{ g6EdCG.V
breakWhile = false; 0$l=ME(
break; Malt7M
} 9x.vz
} VHVU*6_w
if(breakWhile) vgOmcf%;
break; @eMDRbgq;[
lqAU5K{wQ
~!~VC)a*
//count++; W]5kM~Q@
//if(count>4) 6"WR}S0o
// siteStop(); I^/Ugu
} D h]+HF
*{tn/ro6a
S]ZO*+
System.err.println("文件下载结束！"); Vi`+2%4
} DU$]e1
catch(Exception e){e.printStackTrace ();} F0:Fv;
} K @"m0
xr!FDfM.K
{@g3AG%
//获得文件长度 UV)[a%/SB&
public long getFileSize() i:OD)l
{ t)g1ICt
int nFileLength = -1; =sedkrM
try{ srx`" :
URL url = new URL(siteInfoBean.getSSiteURL()); wM(!9Ws3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^mFuZ~g;?
httpConnection.setRequestProperty("User-Agent","NetFox"); NAV}q<@v
?PiJ7|
VZYdCZ&l7
int responseCode=httpConnection.getResponseCode(); E5 H6&XU
if(responseCode>=400) <VB
{ 'mpY2|]\$
processErrorCode(responseCode); h+zJ"\
return -2; //-2 represent access is error s`Z(f:/6*
} Yg/e8Q2
S4s\tA<
EiI3$y3;
String sHeader; GB\.msls
,!kqEIp%
nlHH}K
for(int i=1;;i++) jnt0,y A
{ NWwfNb>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Cst\_j
//Utility.log(in.readLine()); =Xm [
sHeader=httpConnection.getHeaderFieldKey(i); 2uS&A \
if(sHeader!=null) ujB:G0'r
{ -`]B4Nt6
if(sHeader.equals("Content-Length")) TuwH?{ FzK
{ o; 6\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Po&gr@e.V
break; $J[h(>-X
} &of%;>$>M
} Mp?Ev.
else m^U\l9LE
break; )8ctNpQt
} {i~qm4+o
} P\iw[m7O
catch(IOException e){e.printStackTrace ();} Qz{:m
catch(Exception e){e.printStackTrace ();} !#3#}R.$Fl
,V)yOLApVj
nfy"M),et
Utility.log(nFileLength); LB? evewu
g-oHu8
q ]rsp0P2
return nFileLength; S#!PDg
} rv;w`f
(3%NudkwT
<{3VK
//保存下载信息（文件指针位置） w \i#
private void write_nPos() (lwkg8WC
{ qdL;Ii<Y0
try{ }Wn6r_:
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?#rDoYt/Sx
output.writeInt(nStartPos.length); $wdIOfaH
for(int i=0;i<nStartPos.length;i++) :a0qm.EN
{ hCc_+/j|
// output.writeLong(nPos); CcLP/
output.writeLong(fileSplitterFetch.nStartPos); x>!#8?-h
output.writeLong(fileSplitterFetch.nEndPos); PLw;9^<
} p(v+j_ak
output.close(); 6S2D\Bt,_
} *'QD!Tc
catch(IOException e){e.printStackTrace ();} @Ej{sC!0T
catch(Exception e){e.printStackTrace ();} i.)kV B
} Jf|J":S
7 H.2]X
#QXB2x<*
//读取保存的下载信息（文件指针位置） BQ)zm
private void read_nPos() kZ[E493bV
{ *t3fbD
try{ RoJ{ ou@cs
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b9%hzD,MR
int nCount = input.readInt(); B7fURL Rqr
nStartPos = new long[nCount]; bEMD2ABm
nEndPos = new long[nCount]; b_|`jHes
for(int i=0;i<nStartPos.length;i++) V'mQ{[{R
{ [_^K}\/+
nStartPos = input.readLong(); # yAt `
nEndPos = input.readLong(); 2Rc#{A
} KaauX m
input.close(); }<[@)g.h.
} 2x"&8Bg3
catch(IOException e){e.printStackTrace ();} 6*lTur9ni
catch(Exception e){e.printStackTrace ();} v<ASkkh>
} jRmv~]
{<v?Z_!68
BB.^-0up
private void processErrorCode(int nErrorCode) Y#=0C*FS
{ sPyq.oG
System.err.println("Error Code : " + nErrorCode); G yvEc3|@
} o3#qp>R
[GyW1-p33w
yS0!#AG
//停止文件下载 Ovq-rI{
public void siteStop() T[`o$j6
{ rFh!&_
bStop = true; $>hPB[[
for(int i=0;i<nStartPos.length;i++) Y^M3m'd?
fileSplitterFetch.splitterStop(); wI'T Je,
C?fd.2#U
|e!%6Qq3
} NoB)tAvw
} E].hoq7WiB
//负责部分文件的抓取 *?zmo@-
**FileSplitterFetch.java ~Y7>P$G)
*/ 6U Q~Fv`]
package NetFox; }xk85*V
b(Zh$86
7y5`YJ}!
import java.io.*; _D1Uc|
import java.net.*; )\s{\u \
)"/.2S;
3yX^93
public class FileSplitterFetch extends Thread { pZ,=iqr
n`8BE9h^
(u-K^xC
String sURL; //File URL Y``50{7
long nStartPos; //File Snippet Start Position mEeD[dMN
long nEndPos; //File Snippet End Position o%;R4 s,
int nThreadID; //Thread's ID H*51GxK
boolean bDownOver = false; //Downing is over B5{ wSr
boolean bStop = false; //Stop identical XD%@Y~>+
FileAccessI fileAccessI = null; //File Access interface w<#/ngI2
:[xFp}w{
eS-akx^@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mhVdsa
{ H(Pzo+k*
this.sURL = sURL; akATwSrU
this.nStartPos = nStart; q4=Gj`\43
this.nEndPos = nEnd; ', ~
nThreadID = id; /*Iq,"kGz
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f@yInIzRJ
} 3V=wW{;x
+-~8t^
eocq Hwbv
public void run() +i^@QNOa
{ 7IkNS
while(nStartPos < nEndPos && !bStop) ~+|Vzm|S}
{ w_qX~d/
^%ZbjJ7|j
tf[)Q:|
try{ CGw,RNV
URL url = new URL(sURL); c||EXFS}O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e_=TkG1E6
httpConnection.setRequestProperty("User-Agent","NetFox"); 0OCmyy
String sProperty = "bytes="+nStartPos+"-"; H j [!F%
httpConnection.setRequestProperty("RANGE",sProperty); 3D 4-Wo4
Utility.log(sProperty); MTXh-9DA
f|f)Kys%5
Qe4O N3X!
InputStream input = httpConnection.getInputStream(); M/?eDW/
//logResponseHead(httpConnection); tE'^O< K
tVQq,_9C
"`Q&s
byte[] b = new byte[1024]; ~(*2:9*0
int nRead; DwmK?5p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) W{A4*{
{ q"(b}3
nStartPos += fileAccessI.write(b,0,nRead); ;n,xu0/
//if(nThreadID == 1) GHNw.<`l?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #ZkT![`
} r)S:-wP
QL]e<2oPJ
*'w?j)}A9g
Utility.log("Thread " + nThreadID + " is over!"); ?7=c`
bDownOver = true; :A7\eN5
//nPos = fileAccessI.write (b,0,nRead); hKnAWKb0
} JAx0(MZO
catch(Exception e){e.printStackTrace ();} 8Sxk[`qx\K
} IJ]rVty
} ONVhB
TB}6iIe
y0f:N U
//打印回应的头信息 &NKb},~
public void logResponseHead(HttpURLConnection con) CY~ S{w
{ -*A1[Z ?
for(int i=1;;i++) hT`fAn_
{ .^dtdFZ8,
String header=con.getHeaderFieldKey(i); `L LS|S]
if(header!=null) `=V p 0tPI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r=-b@U.fk>
Utility.log(header+" : "+con.getHeaderField(header)); 5G2G<[p5oQ
else !He_f-eZ
break; v-Tkp Yn
} KFgq3snH
} ?;VsA>PV
!\VzX
e@Mg9VwDc
public void splitterStop() O^J=19Ri
{ ayI<-s-
bStop = true; oN2#Jh%dH
} J#W*,%8O
!RP0W
Q6T"8K/
} ~R&rQJJeJ
7Kf
yh2)Pc[
/* e |K_y~
**FileAccess.java ku4Gc6f#gG
*//文件访问(定位，写) i?ZVVE=r
package NetFox; 5vFM0
import java.io.*; 9wlp AK
Qs '_\|/-
yAAV,?:o[
public class FileAccessI implements Serializable{ P3.
~!S/{Un
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uwQgu!|x
RandomAccessFile oSavedFile; IsmZEVuC
long nPos; _aYhW{wW
ht*N[Pi4;
g$ HL::
public FileAccessI() throws IOException i=L 86Ks
{ tm/=Oc1p
this("",0); el U%Z9
} WMHYOJR
=igTY1|af
B{b?j*fHJ
public FileAccessI(String sName,long nPos) throws IOException X!:J1'FE
{ ep~+]7\
oSavedFile = new RandomAccessFile(sName,"rw"); wo+`WnDh
this.nPos = nPos; Q7<Y5+
oSavedFile.seek(nPos); T$`m!mQ4
} ~n8UN<
RP$h;0EQG
^^&H:q
public synchronized int write(byte[] b,int nStart,int nLen) O}%ESAB
{ P4HoKoj2`
int n = -1; Auc&dpW
try{ V@]SKbK}wN
oSavedFile.write(b,nStart,nLen); $@@ii+W}\
n = nLen; -. o,bg
} 1$1>cuu
catch(IOException e) Oe x
{ g4=C]\1
e.printStackTrace (); ^\g.iuE
} yKuZJXGVo
$K+|bb
|||m5(`S
return n; t #Kucde
} uB^"A ;0v
g0"xG}d
,}\LC;31,
} _h4]gZ
4lR+nmAZ
Vpp$yM&?
/* o2B|r`R
**SiteInfoBean.java 5k@T{
*/ @54$IhhT~
package NetFox; b+q'xnA=>
nBd]rak'
1) K<x
public class SiteInfoBean { X31%T"
,tQNL\t
34X]b[^
private String sSiteURL; //Site's URL GApvRR+Z
private String sFilePath; //Saved File's Path nTc#I~\
private String sFileName; //Saved File's Name ovOV&Zt
private int nSplitter; //Count of Splited Downloading File \BH?GMoP
mi$C%~]5m
r>! @Z2%s
public SiteInfoBean() @67GVPcxl
{//nSplitter的缺省值为5 q+4dHS)x
//default value of nSplitter is 5 ~CHcbEWk)W
this("","","",5); Q!3-P
} O7_y QQAA
y`8U0TE3R
A(uo%QE|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =BN<)f^*s
{ Xs|d#WbX
sSiteURL= sURL; 4OLYB9HP_
sFilePath = sPath; Dq%}({+
sFileName = sName; N%'(8%;
this.nSplitter = nSpiltter; <$hv{a
_VjaTw8iM
l%('5oz@\
} !<=(/4o&P
{`k&Q +gY
FeS ,TQ4j
public String getSSiteURL() S&-F(#CF^
{ GIkeZV{4}
return sSiteURL; a#+$.e5
} = 03G~7B>
Z ztp %2c
Yc?S<
public void setSSiteURL(String value) (w2lVL&
{ >);M\,1\I
sSiteURL = value; q)o;iR
} K@DFu5
"M+I$*]
9=6BQ`u
public String getSFilePath() z>0$SBQ-
{ =bP<cC=3b
return sFilePath; qhG2j;
} Z_dL@\#|
yMM2us#*+q
9@lG{9id?
public void setSFilePath(String value) T`j{2
{ /&G|.Cx
sFilePath = value; ZwY mR=
} 6Y6t.j0vN.
gBWr)R
XYD-5pG
public String getSFileName() [>_zV.X
{ 7&HcrkP]
return sFileName; ~.J*_0~Ze
} |;(P+Q4lB
uVhzJu.
k^ fW/
public void setSFileName(String value) )mI>2<Z!
{ DzA'MX
sFileName = value; N}[!QE
} A7XA?>~+|
%dr*dA'
Z eY*5m
public int getNSplitter() C8qSoO4Z
{ J4j:nd
return nSplitter; {*g{9`
} \+/ciPzA-
fuCt9Kjo<
bQ 0Ab"+D
public void setNSplitter(int nCount) ;gu4~LQw
{ FqGMHM\J
nSplitter = nCount; ~#VDJ[Z
} w8N1-D42
} 2*cc26o
9mn~57`y
@q>#]8
/* %[~g84@
**Utility.java FL^t}vA
*/ 9C Ki$L
package NetFox; wL]#]DiE
bUM4^m
(d,OLng
public class Utility { :i {; 81V
Qi=0[
sKs`gi2
public Utility() H"Hl~~U
{ j"pyK@v2B
/[/{m]
=;Co0Q`
} kD1Nq~h2
y0?HZ Xq
//线程睡眠 5&_")k3$*
public static void sleep(int nSecond) {%P2.:
{ ]mNsG0r6
try{ +R;LHRS%
Thread.sleep(nSecond); Uugq.'>
} umAO&S.+M
catch(Exception e) j` * bz-
{ xI#rnx*
e.printStackTrace (); (n2_HePE
} Zy?!;`c*{
} :P%?!'M
*uccY_
//日志 c(b`eUOO
public static void log(String sMsg) s`[V{1m,
{ aZa1eE
System.err.println(sMsg); pEN`6*
} }vgM$o
+7 j/.R
nox-)e
public static void log(int sMsg) Y$)y:.2#
{ ,+C?UW
System.err.println(sMsg); v^p* l0r6:
} <pKOFN%m
} 55] MRv
*J':U>p
VJCj=jX
/* 4W E)2vkS
**TestMethod.java 8-kR {9r
*/ e85E+S%
package NetFox; If'N0^'W
rG[2.\&
%=s2>vv9
public class TestMethod { V!TGFo}
ajM\\a?
Z$('MQ|Ur
public TestMethod() =0;njL(7;
{ ///xx/weblogic60b2_win.exe JLu$UR4
try{ LUpkO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NQiu>Sg
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); KRP6b:+4L
SiteFileFetch fileFetch = new SiteFileFetch(bean); [{vX*q 3B
fileFetch.start(); MA%g-}
} <9$Pl%:
catch(Exception e){e.printStackTrace ();} :zO;E+s
8W7ET@`
=t~]@?]1D
} UQ)^`Zj
i_`Po%
/%{CJ0Y
public static void main(String[] args) LCHw.
{ rCA0c8
new TestMethod(); dww4o~hO
} #0^a-47PA<
} K,P`V &m?
点击下载更多相关资料