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)); z3S"1L7
} =h-EN_[
for(int i=0;i<nEndPos.length-1;i++) \D z? h
{ /FXvrH(
nEndPos = nStartPos[i+1]; F6yFKNK!n
} pIK:$eN!/
nEndPos[nEndPos.length-1] = nFileLength; fG>3gS6&
} *Ts$Hj[
} Q}B]b-c+E
\a;xJzc9
-avxH?;?7
//启动子线程 UwS7B~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Iga+8k
for(int i=0;i<nStartPos.length;i++) Y2l;NSWU
{ aIa<,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '12*'Q+{+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), RDDA^U7y#
nStartPos,nEndPos,i); uNuFD|aQ.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T=-UcF
fileSplitterFetch.start(); y-.{){uaD
} \v-I<"::
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), au50%sA~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); U'" #jT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [#@lsI
nEndPos = " + nFileLength); qtAt=` s
// fileSplitterFetch[nPos.length-1].start(); --l UEo~
^rq\kf*]
xOShO"4Z
//等待子线程结束 xP_%d,
//int count = 0; *Xk5H,:
//是否结束while循环 |33t5}we
boolean breakWhile = false; a~LA&>@
9;{(.K
c8mh#Tbl
while(!bStop) .gC.T`/m
{ iLBORT!;
write_nPos(); 3^ UoK
Utility.sleep(500); _p:n\9k
breakWhile = true; k6(</uRj
[Y*>x2X
Rjq\$aY}%
for(int i=0;i<nStartPos.length;i++) Wu{_QuAB
{ dI%jR&.e;
if(!fileSplitterFetch.bDownOver) ZPE-
{ em,1Yn?
breakWhile = false; d*Mqs}8
break; ;[ Dxk$"
} iQ Xlz]'
} Yn [ F:Z
if(breakWhile) {c3FJ5:
break; %Jh(5
*Lz'<=DLoW
8f~x\.
//count++; w`8H=Hf
//if(count>4) l+2NA4s
// siteStop(); P]^OSPRg
} !Q~>)$Cf^
D['J4B
)s:kQ~+
System.err.println("文件下载结束！"); |0}Xb|+
} T\p>wiY2|F
catch(Exception e){e.printStackTrace ();} )_C>hWvo_
} /hqn>t
Z_bVCe{
1-^D2B[-
//获得文件长度 y[l{ UBue:
public long getFileSize() I>nYI|o1
{ Ek `bPQ5
int nFileLength = -1; .GJbrz
try{ ly34aD/p~,
URL url = new URL(siteInfoBean.getSSiteURL()); q 6UZ`9&z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lbt8S.fx
httpConnection.setRequestProperty("User-Agent","NetFox"); D1-w>Y#
]s5e[iS
R2~y<^.V`Y
int responseCode=httpConnection.getResponseCode(); 5>%^"f
if(responseCode>=400) U`3?bhzua
{ x^)?V7[t
processErrorCode(responseCode); xa'U_]m
return -2; //-2 represent access is error vzfMME17
} m4OnRZYlw
-E6av|c,F
)!rD&l$tE
String sHeader; ?/MkH0[G=
LvS5N)[
Ws3z-U>j
for(int i=1;;i++) Wf"$
{ S)zw[m
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `_)9eGQ
//Utility.log(in.readLine()); U}X'RCM
sHeader=httpConnection.getHeaderFieldKey(i); JXkx!X_{
if(sHeader!=null) vjGJRk|XED
{ =/a`X[9vI
if(sHeader.equals("Content-Length")) 0$`pYW]
{ ] +%`WCr9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z6M5'$\y
break; Y1r'\@L w
} vA:ZR=)F
} 9A4n8,&sm
else v `/nX->
break; 3O*iv{-&
} *>qc6d@'
} Z;~%!
catch(IOException e){e.printStackTrace ();} viU}
catch(Exception e){e.printStackTrace ();} B=>Xr!pM!
BTr;F]W
1yF9zKs&_
Utility.log(nFileLength); Y9f7~w^s
-eV*I>G
,^mEi
return nFileLength; y~]D402Cx
} zFFYl7]
rN#9p+t$
\ CcVk"/
//保存下载信息（文件指针位置） LEnv/t6U
private void write_nPos() y'2w*?
{ "'``O~08/
try{ [V?HK_~
output = new DataOutputStream(new FileOutputStream(tmpFile)); lrHN6:x(Y4
output.writeInt(nStartPos.length); GNmP_N
for(int i=0;i<nStartPos.length;i++) EmUt/]
{ ]g9SUFM
// output.writeLong(nPos); .yUD\ZGJu
output.writeLong(fileSplitterFetch.nStartPos); R6 ej
output.writeLong(fileSplitterFetch.nEndPos); Kk=>"?&
} V]Ccj\Oi
output.close(); w-)JCdS6Tb
} {-7ovH?
catch(IOException e){e.printStackTrace ();} `R (N3
catch(Exception e){e.printStackTrace ();} w_`;Mn%p
} Tg@G-6u0c
.Gr"|uII
3nhQ^zqf
//读取保存的下载信息（文件指针位置） 9({ 9r[U
private void read_nPos() ;6 d-+(@
{ )N^fSenFBn
try{ c{D<+XM
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]S?G]/k}
int nCount = input.readInt(); 2.);OFk+
nStartPos = new long[nCount]; 7?k3jDK
nEndPos = new long[nCount]; W=S^t_F
for(int i=0;i<nStartPos.length;i++) ^oC>,%7
{ qrOesSdc
nStartPos = input.readLong(); j3w~2q"r
nEndPos = input.readLong(); ~IO'"h'w
} &=%M("IlD
input.close(); ;A"i.:ZT
} q2B'R
catch(IOException e){e.printStackTrace ();} wH=7pS"s
catch(Exception e){e.printStackTrace ();} b?Q$UMAbH
} h Ks
Wn;%B].I
'^7Z]K<v
private void processErrorCode(int nErrorCode) ||cI~qg
{ :G9d,B7*
System.err.println("Error Code : " + nErrorCode); dwvc;f-
} Gl{2"!mt=
&u"mFweS
$@{d\@U
//停止文件下载 90JWU$K
public void siteStop() )knK'H(
{ %T<c8w}dP
bStop = true; 1M_6X7PH
for(int i=0;i<nStartPos.length;i++) [}Rs
fileSplitterFetch.splitterStop(); .{;RJ:O
>PdrLwKS
pkG8g5(w
} BB1_EdoG
} 0V"(}!=2a
//负责部分文件的抓取 s&WE'
**FileSplitterFetch.java Qd3ppJn
*/ NV}fcZ
package NetFox; SJ8 ~:"\P
{KTZSs $n
hQzT =0
import java.io.*; o4rf[.z
import java.net.*; bTYR=^9
CIwI1VR^
_,Q -)\
public class FileSplitterFetch extends Thread { i[33u p
Mp5Z=2l5
.Q</0*sp
String sURL; //File URL ed/ "OgA
long nStartPos; //File Snippet Start Position =y?Aeqq\fl
long nEndPos; //File Snippet End Position p*zTuB~e<
int nThreadID; //Thread's ID @1k-h;`,
boolean bDownOver = false; //Downing is over tnb'\}Vn
boolean bStop = false; //Stop identical E7SmiD@)
FileAccessI fileAccessI = null; //File Access interface n*AN/LBp
N^[MeG,8
5P);t9O6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ho%%voJBS
{ b\NY!)B
this.sURL = sURL; bWCtRli}
this.nStartPos = nStart; #'#@H
this.nEndPos = nEnd; *gwo.s
nThreadID = id; Xe ^NVF
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h^H)p`[Gme
} A}uWy^w
SrMfd7H8f
X*)DpbWd
public void run() L`w_Q2{sv
{ [4])\q^q
while(nStartPos < nEndPos && !bStop) HR'F
{ PGTjOkx
bI;u};v
XaU^^K
try{ o|s|Wmx>u
URL url = new URL(sURL); wUS w9xg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }&l%>P
httpConnection.setRequestProperty("User-Agent","NetFox"); dZd]p8
String sProperty = "bytes="+nStartPos+"-"; /5>A 2y
httpConnection.setRequestProperty("RANGE",sProperty); \3rgwbF
Utility.log(sProperty); T%TO?[cN
8X\":l:
0w2<2grQ
InputStream input = httpConnection.getInputStream(); H7{kl
//logResponseHead(httpConnection); }mk z_P(Z
( ~>-6Nb 5
*MCkezW7{
byte[] b = new byte[1024]; tg2+Z\0)4g
int nRead; -?)z@Lc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ZoqE,ucH
{ 2tp95E`(O
nStartPos += fileAccessI.write(b,0,nRead); *2m{i:3
//if(nThreadID == 1) #("E)P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5G#2#Al(F
} ~P-^An^
8hX/~-H
SmP&wNHQf
Utility.log("Thread " + nThreadID + " is over!"); c`)[-
bDownOver = true; k#5Qwxu`
//nPos = fileAccessI.write (b,0,nRead); &x[V<Gq
} :{#w-oC>6P
catch(Exception e){e.printStackTrace ();} a0wpsl iF
} vWYU'_=
} ^{O1+7d[.
_6sSS\
V$MMK
//打印回应的头信息 Ez^wK~
public void logResponseHead(HttpURLConnection con) Q"GZh.m
{ Lnltt86
for(int i=1;;i++) 9iK%@k
{ 5.U|CL
String header=con.getHeaderFieldKey(i); 0*/[z~Z-1
if(header!=null) 7nawnS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OJ# d
Utility.log(header+" : "+con.getHeaderField(header)); 1|7tq
else b5%T)hn=
break; Q,>]f@m
} {@X)=.Zf
} _s0;mvz'
S1*xM
@$|bMH*1:
public void splitterStop() [jKhC<t}
{ JjH141 n%D
bStop = true; &UX:KW`=
} \2 `|eo
gCI{g.[I!
h}GzQry1
} Up1e4mNL
/V>yF&p
`+T"^{ Z
/* 6PRP&|.#
**FileAccess.java AUm5$;o,/
*//文件访问(定位，写) y?xFF9W@H
package NetFox; Zx%6pZ(.
import java.io.*; e:;u_be~
r)f+j@KF
!X<dN..
public class FileAccessI implements Serializable{ {60U6n
eh6=-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^" UZ.@sq'
RandomAccessFile oSavedFile; k4~2hD<|
long nPos; u_%L~1+'
G@6F<L~$1
EpH\;25u
public FileAccessI() throws IOException zCFXQi
{ FWQNO(
this("",0); `z6I][Uf
} bb`8YF+?'
Uizg.<.
j:'8yFi_
public FileAccessI(String sName,long nPos) throws IOException 43BqNQ0
{ D'\gy$9m1
oSavedFile = new RandomAccessFile(sName,"rw"); ]9$^=z%SE
this.nPos = nPos; o+FDkqEN
oSavedFile.seek(nPos); WKONK;U+7
} }Gh95HwE
O g!SFg*
M_f.e!?
public synchronized int write(byte[] b,int nStart,int nLen) @@#h-k%k-
{ 6{?B`gm7g
int n = -1; C.?~D*Q
try{ cFloaCz
oSavedFile.write(b,nStart,nLen); 9<1dps=c
n = nLen; q3/ 0xN+?
} Xny{8Oo<1?
catch(IOException e) '>#8 F.
{ ,^&amWey
e.printStackTrace (); ->a|
} Ox&]{
8QFg6#"O
C"g bol^
return n; )cBO_
} lWk/vj<5
cPPTGpqw
%HcCe[d5l
} A$W~R
_+}#
Q-y`IPtA<
/* J*+[?FXRL
**SiteInfoBean.java Ew*SA
*/ u\o~'Jz
package NetFox; {Z^q?~zC[
e#z#bz2<
$'93:9tg
public class SiteInfoBean { wYN/ }>M
3?bTs =
N<T@GQwkS
private String sSiteURL; //Site's URL `clp#l.ii
private String sFilePath; //Saved File's Path M.fA5rJ^
private String sFileName; //Saved File's Name IQQ QB
private int nSplitter; //Count of Splited Downloading File $9?<mP2-*
hf< [$B
@5*$yi 'Cp
public SiteInfoBean() dc,qQM
{//nSplitter的缺省值为5 -s9()K(vZG
//default value of nSplitter is 5 #,Cz+k*4
this("","","",5); sTw+.m{F
} ^_\%?K_u
:HkXsZ
"*ww>0[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y@2yV(m)o
{ ?OVje9
sSiteURL= sURL; #.@-ng6C
sFilePath = sPath; o4nDjFhh
sFileName = sName; 7(C:ty9
this.nSplitter = nSpiltter; #i=k-FA)H
;2l|0:
W?D-&X^ny
} nG0R1<
(0^ZZe`#j
)_SpY\J
public String getSSiteURL() p;.M.
{ 0n*D](/NK
return sSiteURL; lwm 9gka
} )F,z pGG
%`}nP3
@IV,sze
public void setSSiteURL(String value) qpV"ii
{ LyRW\\z2
sSiteURL = value; I*H($ a
} QVo>Uit
1\-r5e; BE
x%T.0@!8
public String getSFilePath() 8~ u/gM
{ f-Zi!AGh>
return sFilePath; h}4yz96WD
} K>G.HN@
h`f$]_c
Ik-E_U2
public void setSFilePath(String value) y'(a:.%I
{ VE?Aa
sFilePath = value; $0|`h)&
} )Bu#ln"
ji.T7wn1u
5:(/k\9+yv
public String getSFileName() "<&) G{
{ DcN!u6sJ
return sFileName; ~]SCf@pRk
} DGNn#DP
P=R-1V
zJov*^T-C
public void setSFileName(String value) yX/{eX5dr
{ $N\k*=
sFileName = value; &pW2R}
} lN*beOj
7QRkXs
fGoJP[ae
public int getNSplitter() wU|jw(
{ ic}mru
return nSplitter; k%VYAON
} p4D.nB8
JT6}m
RoNE7|gF:
public void setNSplitter(int nCount) 6B+?X5-6DH
{ nWA>u J5
nSplitter = nCount; w@pJ49
} /QT>"
} P=l 7m*m
*P8CzF^>\&
X0]{8v%
/* ~ +h4i'
**Utility.java G|u)eW
*/ wsB
package NetFox; "RgP!
AkCy C1
a(X V~o
public class Utility { c#TV2@
U9jdb9 |
{.ypZ8JU
public Utility() 5+yy:#J]
{ 'I$kDM mwh
\>x1#Vr>#V
aJ}hlM>
} oU se~
Q]e]\J
//线程睡眠 @km4qJZ
public static void sleep(int nSecond) e$/y~!
{ kU,g=+2J
try{ >>|47ps3
Thread.sleep(nSecond); kW0ctGFYlf
} YQb503W"d~
catch(Exception e) rdCs
{ bOSqD[?
e.printStackTrace (); NF7
} z/fSstN
} ,&y_^-|d
70 Ph^e)
//日志 r6GXmr
public static void log(String sMsg) 6\k~q.U@XI
{ &hrMpD6z6i
System.err.println(sMsg); +\$c_9|C+
} !{fu(E
c\/-*OYr<
_>ZC;+c?
public static void log(int sMsg) Kp^"<%RT
{ ix$ ^1(
System.err.println(sMsg); >'4$g7o,
} 'T$Cw\F&
} T?RN} @D
-xbs'[
cQ'x]u_
/* mE_%
**TestMethod.java h=\1ZQKC)
*/ I L,lXB<
package NetFox; v|KIVBkbT
:W6'G@ p
]=9 d'WL
public class TestMethod { {]dG 9
\GQRpJ#h1
WP?]"H
public TestMethod() "a9j2+9
{ ///xx/weblogic60b2_win.exe 2vU-9p {
try{ P_'{|M<?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P(DEf(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -%| ] d ;
SiteFileFetch fileFetch = new SiteFileFetch(bean); [+QyKyhTO
fileFetch.start(); `wZ
} y5F"JjQAa
catch(Exception e){e.printStackTrace ();} Hpa6;eT
w,up`W7,
K\xnQeS<W
} bRrSd:e
`JY+3d,Ui
E)`0(Z:E
public static void main(String[] args) Z=Cw7E
{ w>8kBQ?b
new TestMethod(); &-{%G=5~e%
} M$Bb,s
} 6212*Z_Af
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