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)); f]{1ZU%4
} #r78Ym'aI
for(int i=0;i<nEndPos.length-1;i++) 5(mCBH
{ 5e~ j
nEndPos = nStartPos[i+1]; S&gKgQD"Q
} )M&I)In'
nEndPos[nEndPos.length-1] = nFileLength; 8ItCfbqa6
} H-nFsJ(R!c
} EN5G:hD
tU-#pB>H
%N?W]vbra
//启动子线程 z&6]vN'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n0>5'm%ES
for(int i=0;i<nStartPos.length;i++) t1*BWY
{ !HT>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %B*<BgJ;4F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZEXj|wC
nStartPos,nEndPos,i); +8?R+0P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BXKlO(7
fileSplitterFetch.start(); fwar8 i1
} wz|Q%.%?[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0%q{UW2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k:(e79
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k*zc5ev}
nEndPos = " + nFileLength); 6KZ8 .m}:
// fileSplitterFetch[nPos.length-1].start(); `W.vW8!#
{ c6DT
troy^H
//等待子线程结束 f<$K.i
//int count = 0; Dn{19V.L
//是否结束while循环 TA-(_jm
boolean breakWhile = false; :_I wc=
a{%52B"
"'&>g4F`o
while(!bStop) d=c1WK
{ *cI6&;y
write_nPos(); 2:6Y83
Utility.sleep(500); Aspj*CDu
breakWhile = true; 4P-'(4I)
;_Of`C+
f"Vm'0r
for(int i=0;i<nStartPos.length;i++) X,C/x)
{ ] _]6&PZXk
if(!fileSplitterFetch.bDownOver) -h^} jP8
{ =4w^)'/
breakWhile = false; S9F]!m^i
break; )ZuQ;p
} {TcbCjyw
} $.x?in|_
if(breakWhile) PL$(/Z
break; 6LF^[b/u
ys"mP*wD
BW(DaNt^
//count++; HnKF#<
//if(count>4) V~gUMu4ot
// siteStop(); D/%b@Ls2ze
} l52n/w#qFB
<EMLiiNY
?'8MI|*l%
System.err.println("文件下载结束！"); aaa#/OWQZ
} uN?O*h/(
catch(Exception e){e.printStackTrace ();} :Jsz"vCg&s
} VQW)qOR9
VdN+~+A:
l2KxZteXY0
//获得文件长度 Al-%j- j@-
public long getFileSize() *{p&Fy55
{ JNA}EY^2I.
int nFileLength = -1; hvv>UC/
try{ lLwQridFXh
URL url = new URL(siteInfoBean.getSSiteURL()); =LeVJGF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z6>ZV6(d2^
httpConnection.setRequestProperty("User-Agent","NetFox"); ]mLTF',5
I5<#SW\a?
5l7L@Ey
int responseCode=httpConnection.getResponseCode(); sR0e&Y
if(responseCode>=400) w]P7!t
{ @x>$_:]
processErrorCode(responseCode); x#}eC'Q
return -2; //-2 represent access is error 3~1lVU:
} "ih>T^|
D 5wR?O
HZQ3Ht3Vh
String sHeader; ]bU'G$Qm&s
x)qHeS
\5pAG mgD
for(int i=1;;i++) %dWFg<< |
{ ~9>[U%D
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;g)Fhdy!
//Utility.log(in.readLine()); ~[/c'3+4qn
sHeader=httpConnection.getHeaderFieldKey(i); =K<I)2
if(sHeader!=null) W/F4wEODY
{ c+K=pp@
if(sHeader.equals("Content-Length")) uJ5%JB("E
{ UFY~D"%/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y`_X@Q
break; H2R^t{w
} {3p7`h~
} Ch&]<#E>`
else 87E3pe
break; rOf
} Mh/>qyS*2
} WuQ<AS=
catch(IOException e){e.printStackTrace ();} #1hz=~YO
catch(Exception e){e.printStackTrace ();} .AI'L|FQ%c
v+_Y72h*a
)B5gs%u]
Utility.log(nFileLength); Y\9*e5?`I3
U:p"IY#%
$=QO_t)?
return nFileLength; %oKc?'L0
} xgw)`>p,W
Bst>9V&R
>oaEG5%d
//保存下载信息（文件指针位置） o*ED!y7
private void write_nPos() Lj* =*V
{ -oT+;2\2
try{ 7tO$'q*h
output = new DataOutputStream(new FileOutputStream(tmpFile)); KGwL09)
output.writeInt(nStartPos.length); \#c+vfq
for(int i=0;i<nStartPos.length;i++) Uht:wEr
{ ]~eWr2uG?
// output.writeLong(nPos); GYmBxX87
output.writeLong(fileSplitterFetch.nStartPos); }uj'BO2?
output.writeLong(fileSplitterFetch.nEndPos); f<:SdtG5
} w*kFtNBfU
output.close(); h_"/@6
} G9":z|
catch(IOException e){e.printStackTrace ();} >}(*s^!k
catch(Exception e){e.printStackTrace ();} ]8nm9qmF<
} dnc!=Z89
{h+E&u[zL
$ttr_4=
//读取保存的下载信息（文件指针位置） L"<Eov6
private void read_nPos() BjJ gQ`X
{ }ucg!i3C
try{ w3UJw
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _ShJ3\,K
int nCount = input.readInt(); CPE F,,\
nStartPos = new long[nCount]; )@|Fh@|
nEndPos = new long[nCount]; =C2C~Xd
for(int i=0;i<nStartPos.length;i++) PBnn,#
{ b<cM[GaV~
nStartPos = input.readLong(); n.>'&<H>9
nEndPos = input.readLong(); \-id[zKb
} T0)y5
input.close(); ? NK}q\$
} fT~<C {
catch(IOException e){e.printStackTrace ();} A'R sy6
catch(Exception e){e.printStackTrace ();} m;1exa
} j!n> d
F=c_PQO
zXPj7K*
private void processErrorCode(int nErrorCode) Q'M Ez
{ 3!UP>,!
System.err.println("Error Code : " + nErrorCode); 3goJ(XI
} _j tS-CnO
aJ@qB9(ZBe
]}c=U@D,9
//停止文件下载 . M$D
public void siteStop() a{.n(M
{ ?bA]U:
bStop = true; 9}_f\Bs
for(int i=0;i<nStartPos.length;i++) DYl{{L8@
fileSplitterFetch.splitterStop(); `t2! M\)
tqC#_[~7
P6'I:/V
} $QnfpM%+=
} #=3]bg
//负责部分文件的抓取 U<gw<[>f
**FileSplitterFetch.java )ISTb
*/ O,6!`\ND
package NetFox; r\`m[Q
s``L?9
oI/ThM`=q
import java.io.*; i*>yUav"
import java.net.*; <3CrCEPC
w;_=$L'H&G
7NEn+OI4
public class FileSplitterFetch extends Thread { AV! cCQ
,"ZlY}!Gn
+y(h/NcQ
String sURL; //File URL v[GHqZ
long nStartPos; //File Snippet Start Position g/gLG:C
long nEndPos; //File Snippet End Position N`MQHQ1
int nThreadID; //Thread's ID ?K#$81;[
boolean bDownOver = false; //Downing is over ;hDr+&J|
boolean bStop = false; //Stop identical $ 7!GA9Bn
FileAccessI fileAccessI = null; //File Access interface 0<k!F3=
h^,a 1'
WLb7]rCTp
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @I:&ozy }=
{ }hxYsI"d
this.sURL = sURL; 5Bk
this.nStartPos = nStart; 2Mp;/b!
this.nEndPos = nEnd; fOAb?:D
nThreadID = id; ny}utO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WFG/vzJ
} rK wkj)
PN=yf@<V3F
:f:C*mYvu
public void run() "Q4{6FH+mB
{ K6oLSr+EAK
while(nStartPos < nEndPos && !bStop) L4%LE/t|e
{ *uR'eXW
0jH2.d=
f5Oh#
try{ ,fRb6s-
URL url = new URL(sURL); gw:BKR'o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u)-l+U.
httpConnection.setRequestProperty("User-Agent","NetFox"); KivzgNz
String sProperty = "bytes="+nStartPos+"-"; AaVlNjB
httpConnection.setRequestProperty("RANGE",sProperty); Pipif.
Utility.log(sProperty); <LY+" Y
/FY_LM
00+5a TrE
InputStream input = httpConnection.getInputStream(); k$c!J'qL&
//logResponseHead(httpConnection); tTal<4
pP&~S<[
mDUS9>
byte[] b = new byte[1024]; A:(uK>5{Kk
int nRead; `'`XB0vb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) vr$[
{ =1C9lKm
nStartPos += fileAccessI.write(b,0,nRead); t)h3GM
//if(nThreadID == 1) T=vI'"w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N{0 D<"
} XT)@)c7j
:M16ijkx
"- AiC6u
Utility.log("Thread " + nThreadID + " is over!"); ?FyA2q!
bDownOver = true; dL>ZL1.$
//nPos = fileAccessI.write (b,0,nRead); nm..$QL
} Yhfk{CI
catch(Exception e){e.printStackTrace ();} $v,_8{ !
} xp= ]J UQ
} %?ad.F+7
f|!zjX`
A]1](VQ)4
//打印回应的头信息 u56cT/J1
public void logResponseHead(HttpURLConnection con) cVN|5Y
{ 7o3f5"z
for(int i=1;;i++) *"wsMO
{ NeH^g0Q2,g
String header=con.getHeaderFieldKey(i); GI/o!0"_
if(header!=null) 70@:!HI]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xQ4Q'9
Utility.log(header+" : "+con.getHeaderField(header)); }/=_
else Yyf8B
break; tP3Upw"U
} <?+\\Z!7
} WukD|BCC
mSs%gL]g
74_ji!
public void splitterStop() zrcSPh
{ w5p+Yx=q
bStop = true; ;-59#S&?tB
} bLg1Dd7Q
#~"jo[
iVE+c"c!2&
} kAMt8
czafBO6
0oD?4gn
/* D?$f[+
**FileAccess.java @>?&Mw\c
*//文件访问(定位，写) :^K|u^_>P
package NetFox; QM=X<?m/,=
import java.io.*; 72aj4k]^
7+fFKZFKF
,Ao8QN
public class FileAccessI implements Serializable{ vq|W&
=4G9ev 4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 J}BS/Tr}=
RandomAccessFile oSavedFile; b1-JnEc
long nPos; JVRK\A|R
!I@"+oY<
Xr-eDUEi
public FileAccessI() throws IOException p\Jz<dkN1
{ DEIn:d
this("",0); )tB mSVprl
} OX!9T.j
e(sQgtM6
;sDFTKf
public FileAccessI(String sName,long nPos) throws IOException o@}Jd0D4
{ [E+#+-n7
oSavedFile = new RandomAccessFile(sName,"rw"); K*>lq|iu
this.nPos = nPos; 0EOpK%{
oSavedFile.seek(nPos); t68h$u
} |iJ37QIM
fDf:Jec`[
.Gw;]s3
public synchronized int write(byte[] b,int nStart,int nLen) HKV]Rn
{ CtS*"c,j
int n = -1; nI&Tr_"tm
try{ 72.ZE%Ue
oSavedFile.write(b,nStart,nLen); Ygr1 S(=
n = nLen; w[t!?(![>
} Iq MXd K|
catch(IOException e) to2dkU
{ y8VLFe;
e.printStackTrace (); "YM)bc
} !h4L_D0
pno]Bld'z
zGF_c9X
return n; ,*Jm\u
} w`q):yXX
qhc3 oRe
mJp)nF8r~
} gq!|0
j'g':U
Vv#|%^0
/* HsO4C)/
**SiteInfoBean.java 6"b =aPTi
*/ <J!#k@LY]7
package NetFox; rfku]A$
D=i)AZqMPp
N;Wm{~Zhb
public class SiteInfoBean { Tapj7/0`
eJlTCXeZ|
ED[`Y.;
private String sSiteURL; //Site's URL 1--_E,Su>
private String sFilePath; //Saved File's Path x8+W9i0[1
private String sFileName; //Saved File's Name v@(Y:\>
private int nSplitter; //Count of Splited Downloading File ,onOwPz
fL>>hBCqC
BxVo>r
public SiteInfoBean() 0rP`BK|
{//nSplitter的缺省值为5 bS[;d5
//default value of nSplitter is 5 p'tB4V qT
this("","","",5); O0[.*xG
} !36jtKdM
4Hc+F(
q$7SJ.pF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y%m^V?k
{ )%FRBO]
sSiteURL= sURL; c0h:Vqk-
sFilePath = sPath; ZUPlMHc
sFileName = sName; V~([{
this.nSplitter = nSpiltter; JL.noV3q$
(r78AZ
LX5, _`B
} '@t}8J
?(rJ
C{^U^>bU
public String getSSiteURL() #[=%+*Q
{ S&N[@G
return sSiteURL; 9[31EiT
} x=]PE}<E
2?J[D7
T-S6`^_L
public void setSSiteURL(String value) anxZ|DE
{ #4?Z|_j3
sSiteURL = value; RHe'L36W
} A"ApWJ3
&b~if}vcb
x"7`,W
public String getSFilePath() MhT.Zg\
{ <?h`
return sFilePath; /1OzX'5f
} 1VRexp
Tp-<!^o4
$w%n\t>B
public void setSFilePath(String value) UM[<v9NWE
{ GO3F[l
sFilePath = value; Y367Jr@^N
} =\uQGH
wX7|a/|@
c:>&iB-Yu
public String getSFileName() ZoFQJJK56B
{ 5ctH=t0
return sFileName; N i\*<:_
} Rd#V,[d
B}Lz#'5_
p:g`K#[F
public void setSFileName(String value) gpt98:w:
{ s{q)P1x
sFileName = value; [ QHSCF5
} H#zsk*=QD
F^knlv'
ZMFV iE;8
public int getNSplitter() z^xrB$8 u
{ 4^|;a0Qy]
return nSplitter; ~D[5AXV`^
} @t W;(8-
UM?{ba9
CY{`IZ
public void setNSplitter(int nCount) (+_i^SqK
{ ah1DuTT/G
nSplitter = nCount; Yr7%C
} 7*D*nY4+
} ?=C?3R
#:C?:RMS
<X5'uve
/* c(:qid
**Utility.java C9?R*2L>
*/ Mwm=r//
package NetFox; N|G=n9p
[;IW'cXNq
Lbo8>L(
public class Utility { "!\ON)l*
@I`X{oAA
GoVB1)
public Utility() $m$tfa-
{ =e<;B_~.
y1zNF$<q
W`$D*X0*o
} |(mr&7O
-]!m4xvK
//线程睡眠 v7;zce/~
public static void sleep(int nSecond) ,}9G|$
{ rkp 1tv
try{ bC[TLsh7{2
Thread.sleep(nSecond); %j '_I\
} Y+ZQN>
catch(Exception e) A (:7q4
{ ]}K\&ho2
e.printStackTrace (); F4=+xd >0
} 2(s+?n.N
} Cd>GY
x2 s%qZ#
//日志 1-HL#y*7$
public static void log(String sMsg) }]8n3&*
{ D/T&0
System.err.println(sMsg); HkGA$
} H,/|pP.
35 Y#eU2]
bzI!;P1&
public static void log(int sMsg) zvvF9
{ tcovMn'
System.err.println(sMsg); Cfizh@<
} mPl2y3m%
} /zB;1%m-
lkj^<%N"r
uVO*@Kj+
/* 'Gn-8r+
**TestMethod.java 3ug|H
*/ W%/lBkP
package NetFox; !11x&Db
y:FxX8S$'e
^H0`UKE
public class TestMethod { fB\+.eN
AnB]f~Yjl
9t`Z_HwdCb
public TestMethod() MhE'_sq
{ ///xx/weblogic60b2_win.exe 8 *Fr=+KN
try{ @,b:s+]rp
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); bzz{ p1e
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cfb8kNn~+
SiteFileFetch fileFetch = new SiteFileFetch(bean); x~7_`=}rO
fileFetch.start(); )gO=5_^u*o
} &VY(W{\eY
catch(Exception e){e.printStackTrace ();} ?DAW~+,!7o
1QfOD-lv
>JNK06T
} qr5ME/)z
hq5=>p
Ihe/P {t]J
public static void main(String[] args) /+FZDRf!r
{ fz)i9D@
new TestMethod(); Bld%d:i
} ,zCrix 3
} 9.bMA<X
点击下载更多相关资料