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)); 7fg +WZ
} @+3@Z?!SZ
for(int i=0;i<nEndPos.length-1;i++) i"{ \ >
{ 6H\apgHm
nEndPos = nStartPos[i+1]; X~ AE??
} IC6}s
nEndPos[nEndPos.length-1] = nFileLength; ; iK9'u
} b:,S
} N<\U$\i
]ctlK'.
^\X-eeA
//启动子线程 ;be2sTo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <opBOZ d
for(int i=0;i<nStartPos.length;i++) `6.rTs$<
{ Wy2 pa #Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S]7RGzFe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x[,HK{U|t
nStartPos,nEndPos,i); jJN.(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P1Z+XRWOM
fileSplitterFetch.start(); L(yR"A{FsE
} D-[`wCa,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O<1qU M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V_&>0P{q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", X$L9kZ
nEndPos = " + nFileLength); \Ami-<T
// fileSplitterFetch[nPos.length-1].start(); MMpGI^x!-X
XkWO-L
0t-!6
//等待子线程结束 @@,l0/
//int count = 0; 1HF=,K+
//是否结束while循环 g?'4G$M
boolean breakWhile = false; c:/H}2/C
`(r[BV|h}
eJ+uP,$
while(!bStop) }K!)Z}8
{ b-1cA1#_cP
write_nPos(); !NNq(t
Utility.sleep(500); dJZMzn
breakWhile = true; J~6-}z
>&|C E2'
O;u&>BMk
for(int i=0;i<nStartPos.length;i++) Pw^lp'dO
{ ZR~ *Yofy
if(!fileSplitterFetch.bDownOver) wz-#kH5?
{ HbRDa
breakWhile = false; p/4\O
break; '\$2+*
} 0$-N
} cMCGaaLU
if(breakWhile) poqcoSL"}
break; r.5}Q?
_`/:gkZS
&uh|!lD
//count++; ;E8.,#/a
//if(count>4) =AhXEu^
// siteStop(); 6n{`t/
} ~mqiXr8
`g2DN#q[0
`wJR^O!e
System.err.println("文件下载结束！"); 6]=R#d 7U
} uY,(3x
catch(Exception e){e.printStackTrace ();} 1rr\l`
} y{.s 4NT
4,o|6H
-.8 nEO3
//获得文件长度 L#Mul&r3x0
public long getFileSize() 2L#$WuM~^
{ LRqBP|bjCD
int nFileLength = -1; hJavi>374
try{ <<zYF.9L]
URL url = new URL(siteInfoBean.getSSiteURL()); KaJCfu yp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CzF#feTA
httpConnection.setRequestProperty("User-Agent","NetFox"); s3+^q
.^<4]
wic& $p/%
int responseCode=httpConnection.getResponseCode(); }n+#o!uEf
if(responseCode>=400) eIzT(3(
{ |U*wMYC
processErrorCode(responseCode); X~DI d
return -2; //-2 represent access is error H\OV7=8
} SH"e x,=
gK{-eS
@z8,XW }
String sHeader; &-Bw7v
l-Hp^|3Wq
/bE=]nM
for(int i=1;;i++) >tfy\PY:
{ %!5[3b'h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,O[HX?>
//Utility.log(in.readLine()); "r6DZi(^K
sHeader=httpConnection.getHeaderFieldKey(i); wI!>IV(5
if(sHeader!=null) orB8q((
{ :G/T{87H
if(sHeader.equals("Content-Length")) ,&Iw5E[
{ K:!|xr(1d
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]] R*sd*
break; ('qu#.'
} (Kl96G<Wej
} uqaP\
else q[l!kC+Eh
break; H pHXt78
} l$ABOtM@
} ,J|8P{ZO
catch(IOException e){e.printStackTrace ();} |Co ?uv i
catch(Exception e){e.printStackTrace ();} 4ZY0!'be-R
1l$c*STK
:Ogt{t
Utility.log(nFileLength); 5&WYL
Ccmo(W+0
}g1V6`8&
return nFileLength; %#!`>S)O
} Mqu>#lL
Y#9dVUS
UADD 7d
//保存下载信息（文件指针位置） oMH-mG7:K
private void write_nPos() :J|t! `
{ }%K)R5C
try{ <!ewb=[_$
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3jMHe~.E<
output.writeInt(nStartPos.length); otQulL)T/
for(int i=0;i<nStartPos.length;i++) b5kw*h+/'h
{ C?v_ig
// output.writeLong(nPos); [<;4$}f\
output.writeLong(fileSplitterFetch.nStartPos); '+6H=Qn
output.writeLong(fileSplitterFetch.nEndPos); Z5lE*z
} _^+z2m+~N
output.close(); g4(vgWOW`
} ,G,'#]
catch(IOException e){e.printStackTrace ();} >k gL N
catch(Exception e){e.printStackTrace ();} M=Y}w?
} DH(Qmd
\ /(;LHWQ
DYS|"tSk
//读取保存的下载信息（文件指针位置） 8`e75%f:2
private void read_nPos() =+K2`=y;WF
{ s68&AB
try{ %E\&9,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L0\97AF
int nCount = input.readInt(); e;1n!_l\
nStartPos = new long[nCount]; *#O8 ^3D_c
nEndPos = new long[nCount]; y:6&P6`dx
for(int i=0;i<nStartPos.length;i++) N*~G ]
{ {U:c95#.!S
nStartPos = input.readLong(); RrMC[2=
nEndPos = input.readLong(); iGG;
} Y|eB;Dm1q
input.close(); X2avo|6e
} m&EJ@,H
catch(IOException e){e.printStackTrace ();} "I"(yiKD
catch(Exception e){e.printStackTrace ();} )sWC5\
} FyZp,uD
E^uWlUb{
7M~w05tPh
private void processErrorCode(int nErrorCode) ?LP&VU1
{ 7_,)"J2^
System.err.println("Error Code : " + nErrorCode); wB(A['k
} K8,fw-S%
eK%~`Y
9cJzL"yi
//停止文件下载 y'ZRoakz)
public void siteStop() ?nWK s
{ xHs8']*\
bStop = true; Z)RoFD1]C
for(int i=0;i<nStartPos.length;i++) ES~ykE
fileSplitterFetch.splitterStop(); Ey5E1$w%&
Z:Hk'|q}I
A"wor\(
} iHKWz)0
} ?k$3( -
//负责部分文件的抓取 PCxv_Svf
**FileSplitterFetch.java }Wxu=b
*/ 2yYq/J
package NetFox; ,j{$SuZM
J|k~e,C
dW3q
import java.io.*; zD>:Kj5
import java.net.*; < * )u\A
F8(6P1}E
giU6f!%
public class FileSplitterFetch extends Thread { ?n$;l-m[
Vz$X0C=W;H
(A.%q1h
String sURL; //File URL <"|BuK
long nStartPos; //File Snippet Start Position }@-4*5P3
long nEndPos; //File Snippet End Position B(<;]
int nThreadID; //Thread's ID 6qsT/
boolean bDownOver = false; //Downing is over JJL#Y
boolean bStop = false; //Stop identical h=uv4&
FileAccessI fileAccessI = null; //File Access interface OidF{I*O
G813NoS o
l1X&Nw1W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uj@rv&
{ ,z6&k
this.sURL = sURL; MV"aO@
this.nStartPos = nStart; lNtZd?=>
this.nEndPos = nEnd; n:c)R8X]
nThreadID = id; a8K"Z-LlQ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y993uP
} 16q"A$
]=5nC)|
Do3;-yp>`
public void run() -\mbrbG9H
{ 3c<).aC0f
while(nStartPos < nEndPos && !bStop) Y|bCbaF
{ :-xF=Y(;
?zwPF;L*
KNtsz[#b
try{ nK*$P +[R
URL url = new URL(sURL); \M4/?<g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); psb$rbu7[
httpConnection.setRequestProperty("User-Agent","NetFox"); s_} 1J,Y
String sProperty = "bytes="+nStartPos+"-"; ^+CTv
httpConnection.setRequestProperty("RANGE",sProperty); }]cKOv2
Utility.log(sProperty); `>^2MHF3LT
)L?JH?$C
W(N@`^
InputStream input = httpConnection.getInputStream(); ZJz6{cY
//logResponseHead(httpConnection); (;^VdiJ
)M5:aSRz
q5il9*)d(
byte[] b = new byte[1024]; V!=1 !"}OG
int nRead; $j(2M?.>#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g%1FTl
{ Z_&6<1,H
nStartPos += fileAccessI.write(b,0,nRead); /p|]*={
//if(nThreadID == 1) 0m?v@K' l
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Vw7NLTE}`
} nKn,i$sO/.
'+tU8Pb
ndRy&[f7
Utility.log("Thread " + nThreadID + " is over!"); n,eO6X 4
bDownOver = true; 0*?~I;.2m$
//nPos = fileAccessI.write (b,0,nRead); q=8I0E&q
} yw'b^D/
catch(Exception e){e.printStackTrace ();} IZ /Md@C
} y"=j[.
} 1=C>S2q
fDo )~t*~
Bor_Kib
//打印回应的头信息 ;hsgi|Cy-
public void logResponseHead(HttpURLConnection con) MrIo.
{ |1`|E-S=
for(int i=1;;i++) M%H<F3
{ 8E`rs)A
String header=con.getHeaderFieldKey(i); .%>UA|[~:
if(header!=null) Q8.SD p
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q5'DV!0aSv
Utility.log(header+" : "+con.getHeaderField(header)); 6AgevyVG
else BwO^F^Pr?k
break; f`@$saFD
} ^` N+mlh
} XYD}OddO
)]Xj"V2
V6'"J
public void splitterStop() [4,=%ez
{ y~_wr}.CS
bStop = true; o$I% 1
} &-#!]T-P:E
e=KA|"vxh
> t*+FcD
} kDuN3
il=y m
F0 WM&{v
/* A$G>D3
**FileAccess.java &CW,qY,sh
*//文件访问(定位，写) )&[S*g
package NetFox; F3/aq+<P[
import java.io.*; $fSV8n;Y
Tvr2K84l
OgjSyzc
public class FileAccessI implements Serializable{ /5:C$ik
Sw~jyUEr
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xMI4*4y(
RandomAccessFile oSavedFile; ,yW BO
long nPos; D_r&B@4w
hR"j[
CSx V^
public FileAccessI() throws IOException U1<EAGo|
{ ]v7f9MC'\
this("",0); +ZeHZjd
} 'Dyt"wfo
?<c)r~9]
Y9fktg.
public FileAccessI(String sName,long nPos) throws IOException 8"R;axeD
{ \nM$qr'`B
oSavedFile = new RandomAccessFile(sName,"rw"); 6jFc'
this.nPos = nPos; C*kGB(H7
oSavedFile.seek(nPos); &6nOCU)
} 4bD^Kc4\
1wpT"5B
26|2r
public synchronized int write(byte[] b,int nStart,int nLen) ?qwTOi
{ zJNiAc
int n = -1; V,?i]q;5
try{ {Lu-!}\NP
oSavedFile.write(b,nStart,nLen); >$h*1/
n = nLen; :JW!$?s8H
} xj~/C5@
catch(IOException e) GEU:xn
{ 9dl\`zlA*
e.printStackTrace (); iD=VNf
} *Iv.W7 [
Gv(bD6Rz
1qXqQA
return n; lquY_lrri
} ^Nl)ocHv!
*het_;)+{
qB-9&X
} M^I*;{w6i
J+IQvOn_|
46c7f*1l
/* ,@"Z!?e
**SiteInfoBean.java =qH9<,p`H
*/ |5|^[v
package NetFox; L|4kv
!HyPe"`oL
6@kKr
public class SiteInfoBean { 4Eh 2sI
Nx>WOb98
>&V?1!N"
private String sSiteURL; //Site's URL 5`CPaJT$
private String sFilePath; //Saved File's Path yNVuSj
private String sFileName; //Saved File's Name :|/bEP]p/
private int nSplitter; //Count of Splited Downloading File !l!^`c
|&vQ1o|}
tX)l$oRPr
public SiteInfoBean() tpw0j CVu
{//nSplitter的缺省值为5 &>kklP
//default value of nSplitter is 5 /MHqt=jP6
this("","","",5); csZIBi
} j.O7-t%C
{H OvJ`tM
yyZ}qnbx]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Bs2.$~
{ F?=(4Pyvu
sSiteURL= sURL; c$aTl9e
sFilePath = sPath; kGhWr M
sFileName = sName; udxLHs
this.nSplitter = nSpiltter; J{8_4s!Xt>
0&$+ CWSM
R=ddQ:W6g
} P~nI6/r1
]eA<
Fhw:@@=
public String getSSiteURL() P7r?rbO"
{ `c@KlL*!Q
return sSiteURL; ^/`:o}7K7
} [OFg (R-
~@=:I
5fi6>>
public void setSSiteURL(String value) A-gNfXP,D
{ gNr/rp9A$m
sSiteURL = value; ;}),6R
} ZM"J5}h
z#*M}RR
>xu}eWSz
public String getSFilePath() QW :-q(s
{ ^L}fj$
return sFilePath; O)C y4[
} -.ITcDg
b%>vhj&F
>Ya+#j~CZ
public void setSFilePath(String value) hU=n>g>nx
{ /C"dwh"``
sFilePath = value; ?CGbnXZ4Ug
} F XJI,(:-
Ys,}L.
v{4K$o
public String getSFileName() xXQ#?::m
{ Q:?]:i/*
return sFileName; \M^L'Mkj
} {`fhcEC
1GB$;0 W),
krwY_$q
public void setSFileName(String value) =1g
{ q:Gi Qk-
sFileName = value; ^44AE5TO
} =KJK'1m9
w^N xR,
B6~a `~"
public int getNSplitter() lVY`^pw?
{ -+4:} sD
return nSplitter; ($:s}_<>s
} dK|6p_
!J ")TP=
H <1g
public void setNSplitter(int nCount) Gy0zh|me
{ 3Gi#WV4$
nSplitter = nCount; q:N"mp<%
} u )+;(Vd
} >-rDBk ;K
[f["9(:
c;DWSgIw
/* lot7SXvK
**Utility.java m=i8o `
*/ E>~DlL%
package NetFox; [FLRrTcE
cy|]}n85
Nzj7e 1=
public class Utility { [Lh<k+
@dE|UZ=(
9d{iq"*R
public Utility() %RA8M- d
{ N@J "~9T
}.O,P'k
[eL?O;@BD
} 0eq="|n^|
O~yPe.
//线程睡眠 +=#sam*i
public static void sleep(int nSecond) [*zB vj}G
{ HFYN(nz}[
try{ qPsf`nI7
Thread.sleep(nSecond); vfAR^*7e
} Arh0m. w
catch(Exception e) ],ioY*4G
{ @8X)hpHf
e.printStackTrace (); ^t4T8ejn
} -U;2 b_
} uPbvN[~t
Ut4cli&cC
//日志 VS0 &[bl
public static void log(String sMsg) l6ayV
{ NT?Gl(
System.err.println(sMsg); 7J$
} M\zM-B
5]yQMY\2)
v^2q\A-?
public static void log(int sMsg) c6gRXp'ID
{ 1HYrJb,d
System.err.println(sMsg); :f (UZmV$
} xab1`~%K
} 6J[ {?,
(+}H ih
!mhV$2&r
/* ; V)pXLE
**TestMethod.java ]pi"M3f_
*/ n'a=@/
package NetFox; JK:i-
Lqy]bnY
?EF[OyE
public class TestMethod { M]&F1<
Xy[O
) jBPt&
public TestMethod() K?0f)@\nx
{ ///xx/weblogic60b2_win.exe "<6X=|C
try{ #DjSS.iW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M qq/k J
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b4%sOn,
SiteFileFetch fileFetch = new SiteFileFetch(bean); u*:B 9E
fileFetch.start(); xgV.<^
} Htd-E^/
catch(Exception e){e.printStackTrace ();} KhK:%1po
Gkci_A*
sd|5oz)
} kj_o I5<'
=`fJ
-_&"Q4FR;+
public static void main(String[] args) 5,
{ }gw \w?/
new TestMethod(); k?-GI[@X
} WK;X6`
} ?v8.3EE1\o
点击下载更多相关资料