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)); >a"Z\\dF
} DKfE.p)
for(int i=0;i<nEndPos.length-1;i++) :1 (p.q=
{ @)-sTgn
nEndPos = nStartPos[i+1]; Bt1p'g(V|
} .P.z B}0=
nEndPos[nEndPos.length-1] = nFileLength; !E,A7s
} {*[\'!d--.
} j>]nK~[ka
~ns7O
76wc,+
//启动子线程 n"+[ :w4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $KUos+%
for(int i=0;i<nStartPos.length;i++) \ W?R
{ 53c0 E
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #6AFdNy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), R+nMy=I%8
nStartPos,nEndPos,i); )LJnLo+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hq:&wN7Q
fileSplitterFetch.start(); s@z}YH
} by'DQ 00
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]W Zq^'q.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); y"6y!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }j2Y5
nEndPos = " + nFileLength); rC.eyq,105
// fileSplitterFetch[nPos.length-1].start(); {NPuu?&
Yk'9U-.mc
3' ~gviI
//等待子线程结束 iT;@bp
//int count = 0; DHw&+MY
//是否结束while循环 `+zWu55;
boolean breakWhile = false; FuUD 61JHY
6*qL[m.F[o
%'xb%`t
while(!bStop) Y 2Q=rj
{ *?z0$Kz<,[
write_nPos(); I=7Y]w=
Utility.sleep(500); QV h4
breakWhile = true; !eAo
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dWXstb:[
for(int i=0;i<nStartPos.length;i++) cXR1grz
{ Q~MC7-n>
if(!fileSplitterFetch.bDownOver) Q.9qImgN
{ 5GA\xM-
breakWhile = false; {ekCQeDo
break; nI/kw%<
} j,t#B"hOnp
} CW)Z[<d8
if(breakWhile) T;diNfgg
break; s-Aw<Q)d
h'i{&mS_b
AsPx?
//count++; ;>%~9j1C
//if(count>4) ui"3ak+F
// siteStop(); 'DCFezdf3
} 5jgdbHog]
j}BHj.YuP
{ F'Kk\f%:
System.err.println("文件下载结束！"); ?\U!huu
} yJsH=5A
catch(Exception e){e.printStackTrace ();} &f>eQS=(
} Gy,u^lkk:
j7MO'RX`&
Xt{*N-v\
//获得文件长度 F,GN[f-
public long getFileSize() D?~8za`5
{ lJzl6&
int nFileLength = -1; f`8OM}un&
try{ Q\Gq|e*
URL url = new URL(siteInfoBean.getSSiteURL()); 9Ew7A(BG_3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [xfaj'j=@
httpConnection.setRequestProperty("User-Agent","NetFox"); ewuXpv%vwW
~1*A
`gpQW~*R-;
int responseCode=httpConnection.getResponseCode(); q8Nn%o=5V
if(responseCode>=400) \ A%eG&
{ -/x W
processErrorCode(responseCode); .lBgp=!
return -2; //-2 represent access is error !)qQbk
} e8h,,:l3j
aup6?'G;
dI*'!wK
String sHeader; 1`LXz3uBe
0G <hn8>
KtB!"yy#
for(int i=1;;i++) 1z*kc)=JF8
{ 1|ZhPsD.}g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <&pKc6+{
//Utility.log(in.readLine()); &[a Tw{2
sHeader=httpConnection.getHeaderFieldKey(i); D-IR!js ]
if(sHeader!=null) ~:lKS;PRuK
{ o5Y2vmz?9
if(sHeader.equals("Content-Length")) F52B~@.
{ _Mc>W0'5@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "BVdPSDBk
break; lFUWV)J\
} h(B,d,q"
} 3+xy4G@L
else !r+IXuqV,!
break; S2C]?6cTq
} p T[gdhc
} K"<*a"1I
catch(IOException e){e.printStackTrace ();} JR9$.fGJ
catch(Exception e){e.printStackTrace ();} (QB+%2v
!umEyd@ "
a :HNg
Utility.log(nFileLength); ;`v% sx#
}:z5t,u6
K{cbn1\,H
return nFileLength; !&]z*t
} oc{EuW{Ag
[U\(G
p"`%
//保存下载信息（文件指针位置） d"~(T:=r
private void write_nPos() rrs"N3!aT
{ 99OD=pxQ
try{ ekQrW%\3
output = new DataOutputStream(new FileOutputStream(tmpFile)); BF8"rq}r0
output.writeInt(nStartPos.length); X6RQqen3:
for(int i=0;i<nStartPos.length;i++) #\4 b:dv
{ Qu%D
// output.writeLong(nPos); Di Or{)a
output.writeLong(fileSplitterFetch.nStartPos); ?mRE'#
output.writeLong(fileSplitterFetch.nEndPos); },+~F8B
} +`bC%\T8?
output.close(); U3#dT2U
} {UH9i'y:t
catch(IOException e){e.printStackTrace ();} :DkAQ-<~
catch(Exception e){e.printStackTrace ();} ~fzuwz
} dl l%4Sd
{<w +3Va
BH@b1}
//读取保存的下载信息（文件指针位置） TSo:7&|
private void read_nPos() (E($3t8
{ 8 #oR/Nt
try{ #Ogt(5Sd
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $zkH|] zZ
int nCount = input.readInt(); ErbSl
nStartPos = new long[nCount]; ,#'7)M D8
nEndPos = new long[nCount]; ;RN8\re
for(int i=0;i<nStartPos.length;i++) m-1?\bs
{ _MYx%Z
nStartPos = input.readLong(); FUeq \Wuo
nEndPos = input.readLong(); *+lsZ8'^C
} gs`^~iD]m
input.close(); LxJ6M/".
} Ff"gadRXd
catch(IOException e){e.printStackTrace ();} *M~.3$NN
catch(Exception e){e.printStackTrace ();} FWPW/oC
} rhY_|bi4P
K5ZnS`c;
uhn%lV]
private void processErrorCode(int nErrorCode) o;J;*~g
{ r(uP!n1+
System.err.println("Error Code : " + nErrorCode); (;6s)z
} H`<?<ak6'M
sms1%%~
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//停止文件下载 #*%fu
public void siteStop() 17py).\
{ x3p9GAd#
bStop = true; vC9@,[
for(int i=0;i<nStartPos.length;i++) Q5E:|)G
fileSplitterFetch.splitterStop(); <jd/t19DB
hWGZd~L
gOE_ ]
} gM_:l
} {HZS:AV0
//负责部分文件的抓取 W7!.#b(hU
**FileSplitterFetch.java ^o%_W0_r
*/ ^!>.97*
package NetFox; (5Ky6b9v
r7XD&Y
3sC:jIp
import java.io.*; kfpm=dKL
import java.net.*; %yw=[]Vjze
8[\79|
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public class FileSplitterFetch extends Thread { c2b6B.4
_:,.yRez
w yD%x(
String sURL; //File URL I#l;~a<9z
long nStartPos; //File Snippet Start Position >_#)3K1y8
long nEndPos; //File Snippet End Position GAJ~$AiwHH
int nThreadID; //Thread's ID P06.1
boolean bDownOver = false; //Downing is over (Nt[v;BnO
boolean bStop = false; //Stop identical |[wyc!nY).
FileAccessI fileAccessI = null; //File Access interface 3}M\c)
5!:._TcO
u&3EPu
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YeIe\3x!N
{ ]N\6h(**wy
this.sURL = sURL; $5/\Z
this.nStartPos = nStart; >)%#V<{<
this.nEndPos = nEnd; 7&t~R}&|
nThreadID = id; &|,s{?z2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %<S7
} -><QFJ
O|(o8VS
ZKsQ2"8{M
public void run() tMG@K
{ JTkCk~bX[z
while(nStartPos < nEndPos && !bStop) {F)E\)$G
{ ^fZGX<fH
D5[VK`4Z
n`#+L~X
try{ z\h,SX<U
URL url = new URL(sURL); W8uVd zQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %QE5<2k
httpConnection.setRequestProperty("User-Agent","NetFox"); 8DL hk
String sProperty = "bytes="+nStartPos+"-"; 4^MSX+zt
httpConnection.setRequestProperty("RANGE",sProperty); ^^Bm$9
Utility.log(sProperty); Uf[T_
F(G<*lA
3#<'[TF00t
InputStream input = httpConnection.getInputStream(); $nc, ?)i!
//logResponseHead(httpConnection); oYg/*k7EDX
^(m0M$Wk*
{*nEKPq(_*
byte[] b = new byte[1024]; _3KZME
int nRead; z qO$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Lkp&;+
{ 0i_
nStartPos += fileAccessI.write(b,0,nRead); b7qnOjC
//if(nThreadID == 1) m\} =4b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !a)s`
} $*aE$O6l
As p8qHS
J{^n=X9M0J
Utility.log("Thread " + nThreadID + " is over!"); q1<Fg.-r
bDownOver = true; lSs^A@s
//nPos = fileAccessI.write (b,0,nRead); j$%yw4dsj
} |#:=\gugh
catch(Exception e){e.printStackTrace ();} w1.MhA
} afV P-m4L
} &Ky3Jb<:Gt
ax;{MfsK
T!&jFy*W
//打印回应的头信息 t3Qm-J}wSB
public void logResponseHead(HttpURLConnection con) <Q\H
{ kYmo7
for(int i=1;;i++) vsw7|
{ lbG}noqb
String header=con.getHeaderFieldKey(i); j& <tdORT
if(header!=null) t{[gKV-b
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,?t}NZY&
Utility.log(header+" : "+con.getHeaderField(header)); `6n!$Cxo
else Y+OYoI
break; _u`B3iG
} 6S2r
} lJ("6aT?
\kfcv
$]Rl__;
public void splitterStop() oMz/sL'u
{ 5_PWGaQa
bStop = true; s&Z35IM8|
} p9k4w% ~:
e2qpJ4i
.<0=a|IAz
} 9PUa?Bc`=
v hR twi
Ny]'RS-
/* ;K>{_kf
**FileAccess.java mQmBf|Rl
*//文件访问(定位，写) ntDRlX
package NetFox; %GNUnr$
import java.io.*; 5#yJK>a7
HDa~7wE
RCoeJ|
public class FileAccessI implements Serializable{ Kp$_0
D9e+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9*7Hoi4Ji
RandomAccessFile oSavedFile; #>MO]
long nPos; h85(N
FLi(#9
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public FileAccessI() throws IOException ',L{CQA?c
{ C+X)">/+L
this("",0); 7=$+k]U8
} l6',
z"G`o"4 V
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public FileAccessI(String sName,long nPos) throws IOException }C_G0'"F
{ }R7sj
oSavedFile = new RandomAccessFile(sName,"rw"); \.K\YAM<
this.nPos = nPos; Wg}B@:`T
oSavedFile.seek(nPos); =}B4I
} P@^z:RS*{
~uP r]#
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public synchronized int write(byte[] b,int nStart,int nLen) MLkL.1eGSb
{ >cGh|_9
int n = -1; J-@o@!o
try{ ?/o2#iJx
oSavedFile.write(b,nStart,nLen); /%N31
n = nLen; ws*~$x?7
} L?Kz P.(t+
catch(IOException e) xn%l
{ Qx6,>'Qk'
e.printStackTrace (); /}h71V!
} GI0x>Z+
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O;"*_Xq(`
return n; &:!ZT=
} vjOG?-
d,GtH)(s
[u`17hyX
} \;3B?8wbIl
;'2`M
w>`h3;,2
/* T% /xti5$!
**SiteInfoBean.java >N+bU{s
*/ 1YF+(fk
package NetFox; ?.rH;:9To
,7n;|1`
i6!T`Kau
public class SiteInfoBean { F20wf1^
vF*^xhh
0?J|C6XM#4
private String sSiteURL; //Site's URL EI?d(K
private String sFilePath; //Saved File's Path X/- W8
private String sFileName; //Saved File's Name fD3jwPL
private int nSplitter; //Count of Splited Downloading File ,ZzB#\
)vEHLp.
a>&;K@
public SiteInfoBean() % K9; qJ5
{//nSplitter的缺省值为5 l0:e=q2Ax
//default value of nSplitter is 5 EPE!V>
this("","","",5); E3FW*UNg[y
} lRa 3v Ng
c&| '3i+
'%n<MTL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) w(vE2Y ?
{ ,w9#%=xE
sSiteURL= sURL; O X5Co<u
sFilePath = sPath; t?du+:
sFileName = sName; .pB8=_e:
this.nSplitter = nSpiltter; 4."o.:8x
uI[-P}bSc&
}rj C_q
} #x4h_K Y
oUKBb&&O
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public String getSSiteURL() g|v1qfK
{ BdE`p{
return sSiteURL; cKi^C
} p,[XT`q^
(^s&M
m p|20`go
public void setSSiteURL(String value) _v~D{H&}
{ ')~Y
sSiteURL = value; M<#)D
} q5'yD;[hE
OUIUgej
AihL>a%
public String getSFilePath() s>*Q
{ c5wkzY h
return sFilePath; 3gV&`>@
} bCE7hutl
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IQk#
public void setSFilePath(String value) @sgT[P*ut
{ H.l,%x&K
sFilePath = value; :EQme0OW
} dm/\uE'l
Hl3XqR
j J`Zz
public String getSFileName() +GYI2
{ Ddm76LS
return sFileName; ~f]r>jQM
} syC"eH3{
2l[A=Z
iw~V_y4
public void setSFileName(String value) VM2@{V/=~
{ VhH]n yi7D
sFileName = value; $!l2=^\3
} <igx[2X
fw:^Lyn9$
\@}$Wjsl
public int getNSplitter() O)RzNfI^`N
{ JV?RgFy
return nSplitter; %.Tf u0M
} {YKMQI^O/
\9|]
{Hp}F!X$
public void setNSplitter(int nCount) NBg>i7KQ
{ -t~B@%
nSplitter = nCount; ![P(B0Ct/
} ~0^,L3M
} LA=>g/+i.X
|IcxegE
{Y*]Qc
/* d*\C^:Z
**Utility.java &TkbnDuYd~
*/ <v7KE*#
package NetFox; q@MjeGs%
.e _D3Xp<
4QKE{0NE
public class Utility { ,m?UFRi
~4~Tcn
\'LCC-
public Utility() 4 _U,-%/
{ I_6` Z 0
E_'n4@}Cx
3@cJ=
} 5KH'|z
4h_4jqf=pU
//线程睡眠 CF}Nom)
public static void sleep(int nSecond) +}-W.H%`0
{ 76i rb!-
try{ JbC\l
Thread.sleep(nSecond); BWi 7v
} [A..<[
catch(Exception e) |phWK^
{ (Y.$wMB
e.printStackTrace (); uQ%HLL-W/
} P7x?!71?L
} GY$?^&OO>
CMG`'gT
//日志 r4NT`&`g?
public static void log(String sMsg) 2E;%=e
{ ,^IZ[D>u)
System.err.println(sMsg); HlL@{<
} 2-E71-J
{O&liU4
LjQ1ar\
public static void log(int sMsg) +81+4{*
{ g/X=#!
System.err.println(sMsg); 33KPo0g7
} h'y@M+c(
} [rQ(ae
2#:]%y;\
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/* HToN+z%w3H
**TestMethod.java zkMO3w>
*/ qp_ `Fj:
package NetFox; /GSI.tO
JdYF&~
PKM$*_LcGI
public class TestMethod { XsN#<"f;i
ccRk4xR
4%v+ark8
public TestMethod() ,WDAcQ8\
{ ///xx/weblogic60b2_win.exe h7]]F{r5
try{ 5WJkeG ba
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .9fluAG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P[P72WR
SiteFileFetch fileFetch = new SiteFileFetch(bean); So 6cm|{
fileFetch.start(); [;#.DH]
} %^%-h}1
catch(Exception e){e.printStackTrace ();} g+/U^JIc4l
*pC-`k
Q|<?$.FN"8
} VaIP
` dUiz5o'
/~rO2]rZ@
public static void main(String[] args) ?ZV0
{ i|,A1c"*
new TestMethod(); _>m*`:Wb
} |ShRxE3@'
} fG$.DvJuK
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