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)); DhG2!'N
} U2$e?1y
for(int i=0;i<nEndPos.length-1;i++) j0>S)Q
{ 3P\#moJ
nEndPos = nStartPos[i+1]; p )etl5
} `][~0\Y3m
nEndPos[nEndPos.length-1] = nFileLength; 6vQAeuz<Fq
} cT`x,2
} (zwxrOS
O`g44LW2n
i{I'+%~R
//启动子线程 Xnt`7L<L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; zq80}5%2CT
for(int i=0;i<nStartPos.length;i++) 8RVNRV@g%
{ T12?'JL^r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &q#$SU,$(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f7)}A/$4+
nStartPos,nEndPos,i); D06'"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?=dyU(
fileSplitterFetch.start(); mLd=+&M
} k`62&"T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;gcQ9L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yyPkjUy[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", MlkTrKdGi
nEndPos = " + nFileLength); AA;\7;k{
// fileSplitterFetch[nPos.length-1].start(); 1 9$ufod
puG$\D-[
u3R0_8 _.w
//等待子线程结束 "pa5+N&2-
//int count = 0; Vz1ro
//是否结束while循环 lj/?P9
boolean breakWhile = false; sOa`Tk
#[vmS
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while(!bStop) HTao)`.
{ @ eqVug
write_nPos(); Qf6]qJa|
Utility.sleep(500); ,}2M'DSWa
breakWhile = true; x|<rt966A
>:4}OylhM
tQ< ou,
for(int i=0;i<nStartPos.length;i++) =SA@3)kHH
{ IVzJ|
if(!fileSplitterFetch.bDownOver) pFXDo4eH
{ 9w[7X"#n
breakWhile = false; 68V66:0
break; [h""AJ~t
} vRp =L54z
} A-aukJg9
if(breakWhile) /k|y\'<
break; IFlDw}M!9
3o9`Ko0
%L.,:mtq)
//count++; )?^0<l#s
//if(count>4) (Gf1#,/3~
// siteStop(); cF_ Y}C
} PaP47>(
\|BtgT*$b
'b]GcAL
System.err.println("文件下载结束！"); '*MNRduE6
} ]hpocr
catch(Exception e){e.printStackTrace ();} tu#VZAPW@
} ),v[.9!}:
+v2Fr}
dy-m9fc6%
//获得文件长度 &, hhH_W
public long getFileSize() 5&D)W>{d
{ (s4w0z
int nFileLength = -1; }BlVLf%C
try{ u7ZSs-LuHw
URL url = new URL(siteInfoBean.getSSiteURL()); wo5"f}vd#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oJK1~;:
httpConnection.setRequestProperty("User-Agent","NetFox"); v3x_8n$C9
/@gD 8
|G&<@8O
int responseCode=httpConnection.getResponseCode(); ^8Tq0>n?
if(responseCode>=400) lO3$V JI
{ ZE.nB- H
processErrorCode(responseCode); xbnx*4o0
return -2; //-2 represent access is error h-+9Bv]
} 5"%r,GMU
I7ZY9W(S
}`E5I&r4
String sHeader; Rx<m+=
2Vas`/~u~
`*mctjSN
for(int i=1;;i++) IeLG/ fB
{ R$X1Q/#md
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }dX[u`zQ
//Utility.log(in.readLine()); N`1:U 4}
sHeader=httpConnection.getHeaderFieldKey(i); 2>p K
if(sHeader!=null) %W~Kx_
{ L}UJ`U
if(sHeader.equals("Content-Length")) vQ>x5\r5O_
{ 0+jR,5|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X|^E+ `M4
break; G7yCGT)vQ
} lyNa(3
} Eo 5p-
else f=]+\0MQ
break; Gl}[1<~o
} Ox7v*[x'
} #|k;nFJ
catch(IOException e){e.printStackTrace ();} qL.1N~$2
catch(Exception e){e.printStackTrace ();} x9k(mn%,
_p<W
FivgOa
Utility.log(nFileLength); `9E:V=
@GDe{GG+
h[b5"Uqj
return nFileLength; @]P#]%^D2
} 9\ZlRYnc=
Yf:xM>.%
%K8Ei/p\t]
//保存下载信息（文件指针位置） DXu#07\
private void write_nPos() {R%v4#nk
{ _+[;NBz
try{ dP63bV
output = new DataOutputStream(new FileOutputStream(tmpFile)); uCO-f<b
output.writeInt(nStartPos.length); <aR9,:
for(int i=0;i<nStartPos.length;i++) u>o<ua p
{ c,pR+DP
// output.writeLong(nPos); <^q4^Q[
output.writeLong(fileSplitterFetch.nStartPos); 2eo]D?}
output.writeLong(fileSplitterFetch.nEndPos); LsH&`G^<
} A]L;LkEM
output.close(); }tA77Cm)45
} j hf%ze
catch(IOException e){e.printStackTrace ();} 1;?n]L`T
catch(Exception e){e.printStackTrace ();} JX8Hn |
} QxZYy}2
<9z2:^
(8qD'(@
//读取保存的下载信息（文件指针位置） X`xmV!
private void read_nPos() C"}CD{<H]M
{ KU#w%
try{ DjY&)oce(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -x)Oo`
int nCount = input.readInt(); AdBB#zd
nStartPos = new long[nCount]; 12qX[39/
nEndPos = new long[nCount]; lx_jy>$}r
for(int i=0;i<nStartPos.length;i++) s\2t|d
{ VM=A#}
nStartPos = input.readLong(); eH,r%r,
nEndPos = input.readLong(); {JTO Q 8&
} TbX#K:l
input.close(); &x6Z=|Ers
} E0; }e
catch(IOException e){e.printStackTrace ();} ~R^~?Y%+<
catch(Exception e){e.printStackTrace ();} tmT/4Ia
} Pu/X_D-#Gi
HwfBbWHr'
\) DJo
private void processErrorCode(int nErrorCode) )7!q>^S{B
{ VqGmZ|+8
System.err.println("Error Code : " + nErrorCode); Ey<vvZ
} 8CCd6)cG
]."~)
qd$Y"~Mco
//停止文件下载 [Q+8Ku
public void siteStop() F]o&m::/K
{ SNqw2f5
bStop = true; [ u7p:?WDW
for(int i=0;i<nStartPos.length;i++) F/,K8<|r>
fileSplitterFetch.splitterStop(); 4)MKYhm
xPMTmx?2
v0uDL7
} Mh [TZfV
} IIrh|>d_7
//负责部分文件的抓取 lh^-L+G:Ok
**FileSplitterFetch.java L3}n(KAJj
*/ Su.imM!
package NetFox; N3/G6wn
Mbbgsy3W
`! ~~Wf'
import java.io.*; ;#-yyU
import java.net.*; dxHKXw
#9{N[t
(=#[om(A
public class FileSplitterFetch extends Thread { |NuX9!S
C>l{_J)n
' cM2]<
String sURL; //File URL me-Tv7WL
long nStartPos; //File Snippet Start Position 1^&qlnqH
long nEndPos; //File Snippet End Position A"|y<
int nThreadID; //Thread's ID @c3GJ'"X
boolean bDownOver = false; //Downing is over {2jetX`@h
boolean bStop = false; //Stop identical {Yq"%n'0
FileAccessI fileAccessI = null; //File Access interface EJC{!06L'/
c%|K x
i,#j@R@.C7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2XoFmV),F
{ `y"(\1
this.sURL = sURL; W)F<<B,
this.nStartPos = nStart; JF{yhx,+p
this.nEndPos = nEnd; abog\0
nThreadID = id; XS:W{tL!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Tx+!D'>
} "rxhS; R1>
7oUecyoj
^n! j"
public void run() (41BUX
{ GD*rTtDWn
while(nStartPos < nEndPos && !bStop) poLzgd
{ 9Q\CJ9
( X(61[Lu
5:S=gARz
try{ >i&"{GZ
URL url = new URL(sURL); 73/DOF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `Wc"Ix0
httpConnection.setRequestProperty("User-Agent","NetFox"); VycCuq&M
String sProperty = "bytes="+nStartPos+"-"; etnq{tE5
httpConnection.setRequestProperty("RANGE",sProperty); )y~FeKh
Utility.log(sProperty); %@C(H%obWd
V2Iqk]V%y
++>HU{
InputStream input = httpConnection.getInputStream(); <jt_<p +
//logResponseHead(httpConnection); KMs[/|HX\
d,%e?8x5
^a>3U l{
byte[] b = new byte[1024]; eXs^YPi
int nRead; _:N+mEF
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T"h@-UcTl
{ pr~%%fCh
nStartPos += fileAccessI.write(b,0,nRead); 1co;U
//if(nThreadID == 1) R7'6#2y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a7$]" T 7
} ojmF:hR"
'gBGZ?^N!U
XK*55W&og
Utility.log("Thread " + nThreadID + " is over!"); dUt$kB
bDownOver = true; =w&bS,a"y
//nPos = fileAccessI.write (b,0,nRead); RSv?imi=
} 4lM)ZDg
catch(Exception e){e.printStackTrace ();} <@F.qMl
} 5OJ8o>BF
} B=ckRWq
hB?a{#JL
aNt+;M7g`
//打印回应的头信息 4*`AYx(
public void logResponseHead(HttpURLConnection con) cj[a^ ZH
{ EN,PI~~F
for(int i=1;;i++) !O*'mX
{ iX&eQ{LB
String header=con.getHeaderFieldKey(i); g4eEkG`XTS
if(header!=null) X jPPgI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); st_.~m!/
Utility.log(header+" : "+con.getHeaderField(header)); \*a7o GyH>
else ,(&p"O":
break; >Bw<THx
} Tasmbo^mAF
} 95XQ?%
w}20l F
9#;GG3
public void splitterStop() ?&gqGU}
{ +6zW(Ql/
bStop = true; Pv#Oea?
} "=0(a)01p:
?IN'Dc9&%-
24g\xNnt
} $a@T:zfe
&b__/o
nE&`~
/* i]cD{hv
**FileAccess.java 9mmkFaBQ
*//文件访问(定位，写) ^ gMkQYo(#
package NetFox; WX-J4ieL
import java.io.*; f]_{4Olk
5n0B`A
icrcP ~$A
public class FileAccessI implements Serializable{ MQ#nP_i
H1t`fyri2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xS'Kr.S
RandomAccessFile oSavedFile; jW8,}Xs
long nPos; ?lPn{oB9"
**G5fS.^W
k#g` n3L
public FileAccessI() throws IOException f,}(= u
{ a23XrX
this("",0); hl/) 1sOIR
} FHK{cE
A3uF 0A
4@mK:v%
public FileAccessI(String sName,long nPos) throws IOException i^SPNs=
{ FUO9jX
oSavedFile = new RandomAccessFile(sName,"rw"); w-j^jU><3
this.nPos = nPos; L-9AJk>V
oSavedFile.seek(nPos); C>:,\=y%
} tH)fu%:p
J+(B]8aj
Pf:;iXH?
public synchronized int write(byte[] b,int nStart,int nLen) 5r` x\
{ 6uTFgSqZ
int n = -1; Bjp4:;Bb
try{ `DFo:w!k
oSavedFile.write(b,nStart,nLen); A"}Ib'
n = nLen; &}rmDx
} 5$?)f&M
catch(IOException e) rJM/.;Ag
{ b|DiU}
e.printStackTrace (); e~ZxDAd
} t?(fDWd|-
"?M)2,:A
)Tl]1^
return n; |V&E q>G
} ] :SbvsPm
8yC/:_ML
hDf!l$e.
} 47=YP0r?>T
Qx_]oz]NY
ujf]@L?
/* 8Q(A1U
**SiteInfoBean.java so>jz@!EE
*/ ]@6L,+W"
package NetFox; 98rO]rg
.Cu0G1
u*m|o8
public class SiteInfoBean { d6XdN
Y'+mC
;U&~tpd
private String sSiteURL; //Site's URL B;^1W{%J
private String sFilePath; //Saved File's Path vNQ|tmn
private String sFileName; //Saved File's Name b:Tv Ta
private int nSplitter; //Count of Splited Downloading File iOB*K)U1
dAr=X4LE
{ V$}qa{P
public SiteInfoBean() H1d2WNr[
{//nSplitter的缺省值为5 [85b+SKW
//default value of nSplitter is 5 C({r1l4[D
this("","","",5); lyzM?lK-
} .3CQFbHF
(5l'?7
2@Zw#2|]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9yK\<6}}QH
{ 7P:/ (P
sSiteURL= sURL; NpH:5hi
sFilePath = sPath; hiEosI C
sFileName = sName; 5p>rQq0
this.nSplitter = nSpiltter; ^8=e8O
*pYawT
i3vg7V.
} ~^J9v+
HBm(l@#.
jG%J.u^k
public String getSSiteURL() ()ww9L2
{ T}jW,Ost
return sSiteURL; MP p
} |)OC1=As
#!C|~=
5^Ny6t
public void setSSiteURL(String value) n(9$)B_y
{ ~cf)wrP
sSiteURL = value; K?u:-QX^
} >?jmeD3u
D^S"6v"z
(@NW2
public String getSFilePath() t9r R>Y9
{ `-g$ 0lm7
return sFilePath; XPLm`Q|1#t
} qu0q LM
^ f[^.k$3d
/jSb^1\
public void setSFilePath(String value) ~m4LL[
{ *rVI[kL
sFilePath = value; {S`Rr/E|%
} 5`QfysR5
kyf(V)APPu
oQR?H
public String getSFileName() t!59upbN}3
{ rAk;8)O$
return sFileName; Rl'xEtaN
} O&Y22mu
gZ us}U
ir5eR}H
public void setSFileName(String value) l-2lb&n
{ #!>`$
sFileName = value; & j*Ylj}
} 65GC7 >[
:BF WX
OI:T#uk5
public int getNSplitter() [$M l;K
{ 9t7 e~&R
return nSplitter; nv3TxG
} !iAZEOkRR
<bJ~Ol
]UrlFiR
public void setNSplitter(int nCount) GS*_m4.Ry6
{ G+WCE*
nSplitter = nCount; [OFT!=.y &
} t&-c?&FO\;
} fO837
D=)qd@,K
9y*(SDF
/* +A%zFF3
**Utility.java *7qa]i^]
*/ )O\l3h"
package NetFox; +B7UGI
JEfhr
_+gpdQq\p
public class Utility { ZJQkZ_9@2
crJNTEz
:(I=z6
public Utility() NJKk\RM@7
{ y*8;T v|
eTt{wn;6
5;[0Q
} Xm6M s<z6
R=W$3Ue~,
//线程睡眠 w$749jGx
public static void sleep(int nSecond) _X)]/A%@
{ -./Y
try{ xG(:O@
Thread.sleep(nSecond); z]sQ3"cmX
} tAb3ejCo?
catch(Exception e) O>ZJOKe
{ &<hk&B
e.printStackTrace (); !)c0
} |\]pTA$2
} `U;V-
ik0w\*
//日志 ^1ks`1
public static void log(String sMsg) 6,]2;'
{ mW)"~sA
System.err.println(sMsg); C|rl",&
} w$Mb+b$
[{J1b
os(}X(
public static void log(int sMsg) /`w'X/'VJ
{ -Q!?=JNtQ
System.err.println(sMsg); ezd@>(hJ
} Kw>gg
} 4;w#mzd
_xdttO^N
;~s@_}&
/* dRTpGz
**TestMethod.java H/ub=,Ej*
*/ cH7D@p}
package NetFox; ^9kdd[
J1Y3>40
NO#^_N`#\
public class TestMethod { ,0$b8lb;x/
q5w)i
<7X+-%yb;
public TestMethod() Rh7=,=u
{ ///xx/weblogic60b2_win.exe taOsC!Bp
try{ y] ~X{v
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8\Eq(o}7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7M9s}b%?
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3*b!]^d:D
fileFetch.start(); &S#bLE
} ~K|o@LK
catch(Exception e){e.printStackTrace ();} }Z\+Qc<<
QLTE`t5w3'
ZP%Bu2xd
} NO)vk+
fGLOXbsA
.{]=v
public static void main(String[] args) [g*]u3s
{ u"a$/
new TestMethod(); *$>$O%
} s[@@INU
} Iyvl6
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