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)); D\H/
} ayBRWT0
for(int i=0;i<nEndPos.length-1;i++) |0z;K:5s
{ "Y=+Ls(3o(
nEndPos = nStartPos[i+1]; >5 b/or
} 5IKL#V`3a
nEndPos[nEndPos.length-1] = nFileLength; /Ky__l!bu
} Ux2U*a;
} b5:op@V
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W~Z<1[
//启动子线程 )RsM!}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Xe+,wW3YF
for(int i=0;i<nStartPos.length;i++) LC0d/hM
{ s9oO%e<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LG]3hz9^9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &5t :H 8b
nStartPos,nEndPos,i); :h,`8 Di
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _P?\.W@
fileSplitterFetch.start(); A%\tiZe
} J`*iZvW#Bx
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q# ?wXX47
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M=]5WZO~A
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~LQ[4h<J !
nEndPos = " + nFileLength); ; "3+YTtp
// fileSplitterFetch[nPos.length-1].start(); ~np,_yI
nNmsr=y5
G9g6.8*&
//等待子线程结束 },[;O^Do^{
//int count = 0; Pj?Dmk~
//是否结束while循环 OU7 %V)X5
boolean breakWhile = false; y}08~L?2
0D~ C 5}/4
l|V;Ys5f
while(!bStop) FP"$tt(
{ c6Q(Ygc
write_nPos(); Jg$xO@.
Utility.sleep(500); Ei({`^
breakWhile = true; 23DJV);g8
s0hBbL0DH
;o<m}bGaT
for(int i=0;i<nStartPos.length;i++) Tx%VU8\?n
{ b @;.F!x
if(!fileSplitterFetch.bDownOver) Vga-@
{ 2yo cu!4l
breakWhile = false; o5aLUWi-
break; [t0rfl{.
} efz&@|KR
} G&f7+e
if(breakWhile) FnHi(S|A
break; $A<ESfrs
AKu_~bTk
)fU(AXSP
//count++; &GWkq>
//if(count>4) 'b"TH^\
// siteStop(); #Tp]^ n
} `xKFqx:e
_2vd`k
H'J|U|
System.err.println("文件下载结束！"); `&$B3)Eb
} R UTnc
catch(Exception e){e.printStackTrace ();} qI3NkVA'C
} Z$KV&.=+
@\Js8[wS9@
2)/NFZ
//获得文件长度 g\M5:Qm
public long getFileSize() `^U&#K
{ Ey&aBYR
int nFileLength = -1; HT`1E0G8)
try{ oYM,8 K
URL url = new URL(siteInfoBean.getSSiteURL()); uL?vG6% ^1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7]22"mc
httpConnection.setRequestProperty("User-Agent","NetFox"); d @rs3Q1z
t"s5\;IJ
k<4P6?
int responseCode=httpConnection.getResponseCode(); 19d6]pJ5
if(responseCode>=400) `Xo4q3
{ $(HjI \%l^
processErrorCode(responseCode); ?$%%Mp(
return -2; //-2 represent access is error RB3 zHk%
} yqSY9EX7
"2Op[~V
5^)_B;.f
String sHeader; ^lO76Dz~a
d$;/T('
Qu~*46?0
for(int i=1;;i++) 2Ji+{,?,
{ GHN3PEJ>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ttv9"z
//Utility.log(in.readLine()); ;rBp1[qVe
sHeader=httpConnection.getHeaderFieldKey(i); 5JFV%odo
if(sHeader!=null) WtX>Qu|
{ oO=o|w|T
if(sHeader.equals("Content-Length")) [6gO
{ h{]#ag5`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b1!@v+
break; O]nT>;PXX
} RIhOR8)
} jQtSwVDr
else :%tuNJjj
break; F,v7ifo#f
} Bh`IXu
} R,Ml&4pZ}
catch(IOException e){e.printStackTrace ();} Q~ 0Dfow?
catch(Exception e){e.printStackTrace ();} 68x}w Ae
MTmO>V&O
D[>W{g $
Utility.log(nFileLength); ^9ng)
M#0 @X
7U:=~7GH
return nFileLength; W^xZ+]
} Zg $Tf
.fJ*c
o=9'
//保存下载信息（文件指针位置） YsAF{
private void write_nPos() k|#Zy,
{ ,h!X k
try{ aJ2H.E
output = new DataOutputStream(new FileOutputStream(tmpFile)); wD=am
output.writeInt(nStartPos.length); R$xY8+}V
for(int i=0;i<nStartPos.length;i++) 2z-$zB<vyw
{ %c1FwAC
// output.writeLong(nPos); z~.9@[LG]
output.writeLong(fileSplitterFetch.nStartPos); H7jTQW0rp5
output.writeLong(fileSplitterFetch.nEndPos); WEVl9]b'e+
} $-w5o`e
output.close(); ylkqhs&
} d;g-3Pf
catch(IOException e){e.printStackTrace ();} (9z|a,
catch(Exception e){e.printStackTrace ();} ^Fp=y,D
} #{w5)|S#JD
g8Aj `O
gfVDqDF
//读取保存的下载信息（文件指针位置） <|V'pim
private void read_nPos() 0pNo`Bm
{ 'bm:u
try{ IHVMHOq}'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); yfq>,
int nCount = input.readInt(); yjeL9:jH[
nStartPos = new long[nCount]; q u:To7
nEndPos = new long[nCount]; %Qd3BZ
for(int i=0;i<nStartPos.length;i++) 6!RikEAh
{ -aN":?8(G
nStartPos = input.readLong(); lA4hm4"i(,
nEndPos = input.readLong(); ._ih$=
} ^^ j/
input.close(); _3U|2(E
} l4Y1(
catch(IOException e){e.printStackTrace ();} "7?t)FOo
catch(Exception e){e.printStackTrace ();} !VNbj\Bp
} O*4gV}:G
?'f^X$aS
1 mHk =J~
private void processErrorCode(int nErrorCode) pVz pN8!
{ tnL."^%A2I
System.err.println("Error Code : " + nErrorCode); 1g81S_T .
} gA"<MI'y
i;avwP<0
S[.5n]
//停止文件下载 TnxU/)
public void siteStop() 9C>ynH
{ .h!9wGi`
bStop = true; r?afv.@L2
for(int i=0;i<nStartPos.length;i++) @e={Wy+Vm(
fileSplitterFetch.splitterStop(); uOb2npPj
)BB%4=u@~.
NlMQHma
} ,W8au"
} :@WLGK*u.
//负责部分文件的抓取 cUNGo%Y
**FileSplitterFetch.java *G9 [j$
*/ HIrEv
package NetFox; `~|DoSi^d
`%%?zgY
*XOS.$zGz
import java.io.*; B%y! aQep
import java.net.*; >eu `!8
<]c#)xg
o6/Rx#A
public class FileSplitterFetch extends Thread { .&L^J&V
,0FwBK
=E; #OZO
String sURL; //File URL CHg]Ul
long nStartPos; //File Snippet Start Position w2@"PGR
long nEndPos; //File Snippet End Position o6:45
int nThreadID; //Thread's ID +&?'KZ+Z_v
boolean bDownOver = false; //Downing is over l&$*}yCK
boolean bStop = false; //Stop identical FQQ@kP$.
FileAccessI fileAccessI = null; //File Access interface `TAcZl=8
6l<1A$BQ
=;g=GcVK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException L[1d&d!p
{ OAY8,C=M
this.sURL = sURL; y 'mlee
this.nStartPos = nStart; TXx'7[
this.nEndPos = nEnd; v=j>^FZ
nThreadID = id; GU5W|bS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *|sxa#
} ujow?$&
B6(h7~0(<
v<%]XHN
public void run() XEa~)i{O
{ \N4d_fPj
while(nStartPos < nEndPos && !bStop) `)LIVi"(D
{ v^;-@ddr
7<fL[2-
(}sDm~;s
try{ $e>/?Ss
URL url = new URL(sURL); Cv0&prt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5a8JVDLX^
httpConnection.setRequestProperty("User-Agent","NetFox"); '+tKvTU;
String sProperty = "bytes="+nStartPos+"-"; |x*{fXdMhr
httpConnection.setRequestProperty("RANGE",sProperty); 5Zzr5WM
Utility.log(sProperty); n#)PvV~
C0P*D,
K*0aXr?
InputStream input = httpConnection.getInputStream(); jGJ.Pvc>i
//logResponseHead(httpConnection); ;gdi=>S_
S!u6dz^[$X
Al=(sHc'
byte[] b = new byte[1024]; ip<15;Z
int nRead; _r~!O$2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) IU7$%6<Y
{ e21E_exM0
nStartPos += fileAccessI.write(b,0,nRead); U8EJC .e&O
//if(nThreadID == 1) ;5-R=e(KA
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !-F^VGD(8
} 7 kEx48
Oi6f8*,
h=!M6yap<
Utility.log("Thread " + nThreadID + " is over!"); : x>I- 3G
bDownOver = true; P"oYC$
//nPos = fileAccessI.write (b,0,nRead); f<'n5}{RO0
} a$~IQ2$|6
catch(Exception e){e.printStackTrace ();} m*\B2\2gJ
} f2`P8$U)R
} B{[f}h.n
R|nEd/'<
~?2rGE
//打印回应的头信息 #Tup]czO
public void logResponseHead(HttpURLConnection con) /A%om|+Gq
{ ?s1u#'aO
for(int i=1;;i++) s*aH`M7^0
{ +Gk! t]dy
String header=con.getHeaderFieldKey(i); =X)Q7u".7
if(header!=null) ,Le&I9*%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Y;'VosTD
Utility.log(header+" : "+con.getHeaderField(header)); F_ ,L2J
else ;r gH}r
break; x-w`KFS
} j2< !z;2
} eo>/
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[q|?f?Zl
public void splitterStop() cWgbd^J
{ TS\9<L9S
bStop = true; Uc_'3|e
} LDT'FwMjy
Y1#-^,qg
c-[Q,c
} UOn!Y@
7(yXsVq
}f<fgY
/* [?Mc4uT{
**FileAccess.java C/{nr-V3u
*//文件访问(定位，写) *p""YEN
package NetFox; `G_(xN7O
import java.io.*; Es.toOH$S
73'U#@g6
(eCF>Wh^m
public class FileAccessI implements Serializable{ 9 Q0#We*
_F}IF9{?G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _#/!s]$d#
RandomAccessFile oSavedFile; [ c ~LY4:
long nPos; H.jLGe>
[$hptQv
~a|^?7@p
public FileAccessI() throws IOException #)W8.
{ ?)Tz'9l
this("",0); ?l)}E
} ^Nd|+}
dH ^b)G4
tqff84
public FileAccessI(String sName,long nPos) throws IOException `f\5p+!<7R
{ =XZF.ur
oSavedFile = new RandomAccessFile(sName,"rw"); R=][>\7]}
this.nPos = nPos; ;FV~q{
oSavedFile.seek(nPos); !L&=?CX
} Zp/qs z(]
^2&O3s
O!#L#u53
public synchronized int write(byte[] b,int nStart,int nLen) \SYPu,ZT
{ <7vIh0
int n = -1; I><99cwFI
try{ ?)A]q' O
oSavedFile.write(b,nStart,nLen); x:f|3"\s
n = nLen; OvyB<r
} u#zP>!
catch(IOException e) R-g>W
{ M!xm1-,[
e.printStackTrace (); DiZ!c"$
} UPfFT^=y
iFAoAw(
377j3dP
return n; \j,v/C@c-
} Ff)~clIK '
H3 A]m~=3
y9V;IXhDc
} "ay,Lr
k#8S`W8^
DuTlYXM2^
/* n.Ur-ot
**SiteInfoBean.java %0ll4"
*/ eZ8Y"i\!y
package NetFox; {f@xA
*tq|x[<
o*O"\/pmF
public class SiteInfoBean { OH-~
~>Hnf_pZO
1+16i=BF)
private String sSiteURL; //Site's URL N=O+X~
private String sFilePath; //Saved File's Path [[*0MA2Y
private String sFileName; //Saved File's Name bWX[<rh'
private int nSplitter; //Count of Splited Downloading File 4%',scn
~xlMHf
+LQs.*
public SiteInfoBean() :=iM$_tp'
{//nSplitter的缺省值为5 W(u6J#2
//default value of nSplitter is 5 ZbZAx:L
this("","","",5); ;y?D1o^r8W
} `>`K7-H
eB(S+p?
@w#gRQCl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) JR? )SGB
{ i(&6ys5
sSiteURL= sURL; 'y+bx?3Z
sFilePath = sPath; p5twL
sFileName = sName; NE=#5?6%g7
this.nSplitter = nSpiltter; _Cv[`e.
*uI hxMX
K-"HcHuF
} 3zA8pI w
V<~_OF
1,%#O;ya
public String getSSiteURL() rHC+nou
{ QC\,
return sSiteURL; OIXAjU*N
} RAv RNd
(N~zJ.o
8Y{}p[UFT
public void setSSiteURL(String value) wH(vX<W-E
{ G+ $)W u
sSiteURL = value; zP{<0o
} <QkN}+B=
V~]'+A q>
n&3iv^
public String getSFilePath() T ,O<LFv
{ s5zGg]0
return sFilePath; RIVL 0Ig
} DiYJlD&
}]39 iK`w
v8'`gY
public void setSFilePath(String value) y3@x*_K8
{ (Qh7bfd
sFilePath = value; mP5d!+[8
} Ch \ed|u
{'c%#\
WDH[kJ
public String getSFileName() u':0"5}
{ :m)Rmwn_
return sFileName; giSG 6'WA
} ~*cY& 9
]UCk_zWsn1
. tH35/r
public void setSFileName(String value) k`2B9,z
{ yZ?_q$4kEI
sFileName = value; k^dCX+
} ?{.b9`
8x^H<y=O
mtWx ?x
public int getNSplitter() v_@#hf3
{ 3R:7bex
return nSplitter; pRxlvVt
} -MHX1`P:Sn
V=l Q}sBY
Lm*LJ_+ B
public void setNSplitter(int nCount) 53u.pc
{ kq1M<lk
nSplitter = nCount; tEWj}rX
} N5w]2xz!
} )q]j?Z.
jKCqH$
a9@l8{)RX
/* ".Deu|>
**Utility.java ^?^|Y?f2P?
*/ dn)tP6qc/
package NetFox; J\dhi{0
4G;`KqR@
dS;|Kl[Om
public class Utility { c9g\7L,Z
H'= i
xU\:Vid+A
public Utility() 1O3<%T#LOZ
{ c;|&>Fp
pqQdr-aR=
<>*''^
} l&^[cR
_7j/[
//线程睡眠 i2ml[;*,N
public static void sleep(int nSecond) _qzo):G.s
{ 4Tzu"y
try{ ry'^1~,
Thread.sleep(nSecond); &A5[C{x
} Jn:GA@[I
catch(Exception e) a+a%}76N
{ {R{%Z
e.printStackTrace (); : .w'gU_
} ]kplb0`
} 4;c_%=cU
VY&9kN
//日志 85@6uBh
public static void log(String sMsg) 8DS5<
{ knK=ENf;e
System.err.println(sMsg); ;'18
} 1\608~ZH
k}0
"6NNId|Y
public static void log(int sMsg) M"$RtS|h
{ ]MA)='~
System.err.println(sMsg); bQN4ozSi
} by y1MgQd
} sImxa`kb
J0WXH/:
K?OX
/* C^42=?
**TestMethod.java /h.3<HI."*
*/ VX>t!JP p
package NetFox; Z%n.:I<%ZV
D>x'3WYR
LYq2A,wm$
public class TestMethod { mlw BATi
$XU$?_O
V_d%g<n4
public TestMethod() UCj#t!Mw
{ ///xx/weblogic60b2_win.exe Dp6"I!L<|
try{ 5~R{,]52
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S| -{wC%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w>q_8V_K
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]aW.b_7<9
fileFetch.start(); [MXXY
} ?QIQ,?.
catch(Exception e){e.printStackTrace ();} <sFf'W_3{
yExyx?j.
m}'@S+k^
} Rw=E_q{
,G/X"t ~
'nDT.i
public static void main(String[] args) I/-w65J]
{ CY).I`aJ
new TestMethod(); r`g;k&"a
} z4fK{S
} ]:#$6D"
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