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)); Z:^3Fm->+
} ^srs$ w]
for(int i=0;i<nEndPos.length-1;i++) Oxj(g;}
{ *H*\gaSh
nEndPos = nStartPos[i+1]; Y-~;E3(
} GC?S];PL
nEndPos[nEndPos.length-1] = nFileLength; bX&e_Pd
} T/Q==Q{W:
} MCd F!{
i* gKtjx
"aA_(Ydzj
//启动子线程 <?4cWp|i
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Y eO-gY[b
for(int i=0;i<nStartPos.length;i++) a 8-;
{ MLeX;He
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `:3&@.{T(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), TK %<a/
nStartPos,nEndPos,i); oek #^:pF
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x/_dW
fileSplitterFetch.start(); EqQ3=XMUL@
} xXPUrv5zO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9 P~d:'Ib
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xH@'H?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", tx)OJY
nEndPos = " + nFileLength); G{O\)gf
// fileSplitterFetch[nPos.length-1].start(); MC6)=0:KX
X\'E4
z.j4tc9F/5
//等待子线程结束 iP,v=pS6
//int count = 0; ?q6Z's[
//是否结束while循环 8E 9{ Gf
boolean breakWhile = false; a+'}XEhSC:
ooDdV >
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while(!bStop) }bCK
{ ;YM]K R;
write_nPos(); ex=)H%_|
Utility.sleep(500); 1^tSn#j
breakWhile = true; zM\IKo_"
:r-.r"[m-
H}a)^90_
for(int i=0;i<nStartPos.length;i++) ~K%k 0kT
{ Md?acWE*L
if(!fileSplitterFetch.bDownOver) c+wuC,
{ uYabJqV
breakWhile = false; ]'6'<S
break; K7S754m
} ysl8LK
} i.F8
if(breakWhile) gu!](yEgl
break; o[n<M>@
qr9Imr0w<
!^]q0x
//count++; b.@H1L
//if(count>4) F/xCG nP-
// siteStop(); u(8~4P0w
} F6DxvyANr
YV4 :8At1
MN\i-vAL8
System.err.println("文件下载结束！"); EZ*t$3.T
} 5'62ulwMP=
catch(Exception e){e.printStackTrace ();} NQg'|Pt(%
} b24di
Fdr*xHx$P
2*Va9HP!q
//获得文件长度 a" ^#!G<+
public long getFileSize() TG4^_nRl
{ gh'kUZG a
int nFileLength = -1; 89db5Dx
try{ LH,]vuXh
URL url = new URL(siteInfoBean.getSSiteURL()); 98h :X%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VZt;P%1;h
httpConnection.setRequestProperty("User-Agent","NetFox"); \u{Jf'g
r)c+".0d^
G I&qwA
int responseCode=httpConnection.getResponseCode(); uvR0TIF4
if(responseCode>=400) gj[zka0_
{ U{HyxZ|q<
processErrorCode(responseCode); n$IWoIdbGN
return -2; //-2 represent access is error *&h6*zP?
} h)7v1,;w'
$1b]xQ
}+*w.X}L
String sHeader; 3_C98ClE
ZMP?'0h=
3Hy%SN(
for(int i=1;;i++) L,E-z_<p
{ ?ISI[hoc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "k/;`eAP
//Utility.log(in.readLine()); v*smI7aH
sHeader=httpConnection.getHeaderFieldKey(i); "IOC[#&G
if(sHeader!=null) 8?A@/
{ o@Scz!"g
if(sHeader.equals("Content-Length")) )\RzE[Cb
{ ix(U:'{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =kwb` Z/a
break; 7Y%!,ff
} yB 1I53E
} !?S5IGLOj
else V[4(~,9
break; KSF5)CZ5
} BN_!Y)Fl
} 5z9JhU
catch(IOException e){e.printStackTrace ();} G~JCgi
catch(Exception e){e.printStackTrace ();} _'H2>V_
^6ExW>K
>F,$;y52
Utility.log(nFileLength); OY+!aG@.
LQ~LB'L
Z`^ K%P=
return nFileLength; Z@<q/2).|
} }m9S(Wal
[t {vYo
_e;N'DZ
//保存下载信息（文件指针位置） d]^\w'w$
private void write_nPos() !1D%-=dWX
{ "1_{c *ck
try{ yW%&_s0
output = new DataOutputStream(new FileOutputStream(tmpFile)); BT&rp%NO6l
output.writeInt(nStartPos.length); czXI?]gg,
for(int i=0;i<nStartPos.length;i++) <+ -V5O^
{ ;Gjv9:hUn
// output.writeLong(nPos); jB*9 !xrd,
output.writeLong(fileSplitterFetch.nStartPos); 5}<.1ab3V
output.writeLong(fileSplitterFetch.nEndPos); qPp1:a"
} Tbe_xs^
output.close(); LBW.*PHW
} iSnIBs9\
catch(IOException e){e.printStackTrace ();} .a ~s_E
catch(Exception e){e.printStackTrace ();} 0*37D5jH
} 3FGbQ_
#k"1wSx16
}".\ 4B$n
//读取保存的下载信息（文件指针位置） tpN]evp|
private void read_nPos() /E=h{|
{ jXc5fXO N
try{ d,Hf-zJ%~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PpX{+^z-%
int nCount = input.readInt(); L-^# 02
nStartPos = new long[nCount]; XMjI}SPG
nEndPos = new long[nCount]; p=:7 atE
for(int i=0;i<nStartPos.length;i++) N{?Tm`""
{ I@8+k&nXS
nStartPos = input.readLong(); v]LFZI5
nEndPos = input.readLong(); fs]#/*RR
} .d<~a1k
input.close(); P58\+9d_
} s4\SX,
catch(IOException e){e.printStackTrace ();} X7'h@>R
catch(Exception e){e.printStackTrace ();} wxdh?sQ
} ,apd3X%g
tXssejiE%
$K=K?BV[
private void processErrorCode(int nErrorCode) TKj/6Jz|
{ ui s:\Uc
System.err.println("Error Code : " + nErrorCode); T=hm#]
} 'US:Mr3
44Seq
Y!K^-Y}
//停止文件下载 9+WY@du+
public void siteStop() *Y|lO
{ 34&u]4=L)
bStop = true; V Z4nAG
for(int i=0;i<nStartPos.length;i++) mafAC73
fileSplitterFetch.splitterStop(); fJSV)\e0
fS;m+D!j@
avYh\xZ
} e B9m4
} ;XD>$t@
//负责部分文件的抓取 7)ES!C
**FileSplitterFetch.java :X1`wBu
*/ -ucz+{
package NetFox; <MI$Nl
"B_5Y&pM`
|THkS@Br
import java.io.*; @j)f(Zlu#
import java.net.*; ~FK+bF?%
rRF+\cP?.
Z_eqM4{
public class FileSplitterFetch extends Thread { Mt7X<?GZm
#R"9)vHp
0C4*F
String sURL; //File URL IdN%f]=/
long nStartPos; //File Snippet Start Position cG~_EX$
long nEndPos; //File Snippet End Position T1g:gfw@
int nThreadID; //Thread's ID s5_1}KKCs
boolean bDownOver = false; //Downing is over V!yp@%D
boolean bStop = false; //Stop identical ;n:H6cp
FileAccessI fileAccessI = null; //File Access interface |r<.R>
$w2[5|^S
juve9HaW
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Z(Ls#hp
{ Px^<2Q%Fs
this.sURL = sURL; Yc|-sEK/
this.nStartPos = nStart; b_)QBE9
this.nEndPos = nEnd; {4V:[*3
nThreadID = id; &L[8Mju6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B8BY3~}]
} ]%ZjD
$AL|d[[T[
)nbyV a
public void run() Z;dwn~Tw
{ ^YB\\a9
while(nStartPos < nEndPos && !bStop) T^f&58{ 7
{ 0X}w[^f
!Cv<>_N).
`gA5P %
try{ R,(+NT$
URL url = new URL(sURL); `qYc#_ELv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xr1I8 5kM
httpConnection.setRequestProperty("User-Agent","NetFox"); 0lJBtk9wn
String sProperty = "bytes="+nStartPos+"-"; FrE/K_L
httpConnection.setRequestProperty("RANGE",sProperty); i >/@]2
Utility.log(sProperty); fu7[8R"{
;#Crh}~
QKL]O*
InputStream input = httpConnection.getInputStream(); QtO[g
//logResponseHead(httpConnection); =-a?oH-
y+~Aw"J}
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byte[] b = new byte[1024]; O+3D 5*
int nRead; (t"YoWA#m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C9^elcdv
{ )Sh;UW
nStartPos += fileAccessI.write(b,0,nRead); u.xA}yVS
//if(nThreadID == 1) U%SNROj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =fu_ Jau}
} 0^-b}
8)2u@sx%
ES:p^/=*
Utility.log("Thread " + nThreadID + " is over!"); *^&iw$Qx3
bDownOver = true; b^|,9en
//nPos = fileAccessI.write (b,0,nRead); 6`{)p&9
} r0XGGLFuZl
catch(Exception e){e.printStackTrace ();} >=RHE@
} :[$i~V
} *TMM:w|1
`:^)"#z)
X#\P.$
//打印回应的头信息 0^tJX1L
public void logResponseHead(HttpURLConnection con) I?xhak1)lu
{ ^LAS9K1.
for(int i=1;;i++) C J}4V!;|
{ =*O9)$b
String header=con.getHeaderFieldKey(i); G#=b6DB
if(header!=null) S3[oA&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); L:];[xa%
Utility.log(header+" : "+con.getHeaderField(header)); sjgxx7
else Q0oDl8~
break; '\3.isTsx
} DW;.R<8
} l>Oe ,`9O
;:K?7wfXn
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public void splitterStop() ^<H#dkECG
{ <MDFfnj
bStop = true; m$e@<~To
} [E&"9%K
TuT=
@zpHemdB
} m0K2p~
"nS{ ;:
vcUM]m8k
/* -1Ki7|0,
**FileAccess.java Szob_IEq,
*//文件访问(定位，写) RI].LB_
package NetFox; Tr+Y@]"
import java.io.*; os0"haOI9h
gcY~_'&u
)I1V2k$n
public class FileAccessI implements Serializable{ m+JGe5fR<
:y)&kJpleP
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?_`P;}4#
RandomAccessFile oSavedFile; n ;fTx
long nPos; .M#>@~XR
&qj&WfrB,
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public FileAccessI() throws IOException I5 7<0
{ [AK%~Kg9
this("",0); {s^n|b}
} So0,)
W!Os ci
oI"Fpo
public FileAccessI(String sName,long nPos) throws IOException SX<>6vH&
{ N,'qMoNf
oSavedFile = new RandomAccessFile(sName,"rw"); (]uoN4
this.nPos = nPos; 7*W$GCd8
oSavedFile.seek(nPos); Pxuz {
} N=}Z#
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;Z0cD*Jb
public synchronized int write(byte[] b,int nStart,int nLen) j-\^ }K.&
{ s#CEhb
int n = -1; !haXO
try{ 5|H(N}S_
oSavedFile.write(b,nStart,nLen); MhXm-<4
n = nLen; c;fyUi
} 5^R#e(mr
catch(IOException e) +R jD\6bJb
{ 6O?Sr,
e.printStackTrace (); G?X,Y\Lp
} [}Yci:P_ +
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return n; UVi/Be#|
} 9(\N+
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<.]&FPJ
} 'g, x}6
]$%4;o4O
gf8U &;
/* nWg)zj:
**SiteInfoBean.java k.VOS0
*/ 9!<3qx/
package NetFox; 3).c[F^l
mr\L q~*c
m,"tdVo.
public class SiteInfoBean { <qZ+U4@I)
"U~@o4u;
JN|#
private String sSiteURL; //Site's URL C)dYAq3,8
private String sFilePath; //Saved File's Path ;&:Et
private String sFileName; //Saved File's Name Aba%Gh
private int nSplitter; //Count of Splited Downloading File \{^yB4F_Z
}tgn1xpx
`RLrT34
public SiteInfoBean() 1T^L) %&p_
{//nSplitter的缺省值为5 " ~hjB
//default value of nSplitter is 5 gG?*Fi
this("","","",5); {dH<Un(4Z
} Ya{1/AaM
4E94W,1%,Y
LPgI"6cP
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .EELR]`y7I
{ |xC TX
sSiteURL= sURL; X64I~*
sFilePath = sPath; vWga>IGM
sFileName = sName; (9lx5
this.nSplitter = nSpiltter; WM7/|.HQ
> %*X2'^
+ {dIs
} e;Z`&
qOanu
{;~iq
public String getSSiteURL() (M?Q9\X
{ _ q1|\E%`h
return sSiteURL; \d`Sz *
} LR.+CxQ
u 9TlXn
-C]a2
public void setSSiteURL(String value) ~#Mx&mZ
{ smS0Rk
sSiteURL = value; M)RQIl5
} c3BL2>c
Gi2Ey37]O
O/~^}8TLL
public String getSFilePath() f.CI.aozW
{ K?I&,t_*R
return sFilePath; ~n\ea:.
} -L3RzX
${2fr&Tp
y=`(`|YW}`
public void setSFilePath(String value) 2C&%UZim;P
{ a VMFjkW
sFilePath = value; n[-!Jp[
} &g {_.n,
>C66X?0cd
1W7BN~p14
public String getSFileName() h0pr"]sO;$
{ o\gQYi
return sFileName; i)DXb
} .`RC,R`C
%05a>Rf&
| Ylk`<
public void setSFileName(String value) gWPa8q<b
{ N/=3Bs0y-
sFileName = value; 1r4/McB
} tYa*%|!v
I-hhHm<@
jgIzB1H
public int getNSplitter() 3S?+G)qKo
{ hdb4E|'A
return nSplitter; ?^Ux+mVE
} jXR+>=_
<rF
7mBL#T2
public void setNSplitter(int nCount) _ RYZyw
{ K@lV P!z
nSplitter = nCount; JR)rp3o-
} xnOlV
} [J Xrj{
9m!fW|4
tsD^8~ t|h
/* 55\mQ|.Jn
**Utility.java .@V>p6MV
*/ B:.rp.1
package NetFox; EUqG"h5#A{
z`SkKn0f Y
j&5Xjl>4
public class Utility { \:7EKzQ
//|Vj | =
P!EX;+7+x
public Utility() g7-K62bb
{ ^Quy64M
4r&~=up]
'~0&m]N
} a/fYD2uNo
;;5i'h~?]J
//线程睡眠 \eCdGx?
public static void sleep(int nSecond) AJu.
{ 8EA?'~"
try{ IgL8u
Thread.sleep(nSecond); *Y~64FM
} Po3W+;@
catch(Exception e) ^Du_e(TiyK
{ ZxQP,Ys_Y
e.printStackTrace (); 8b!_b2Za
} F^-4Pyq@
} @dNbL}qQ
<5%We(3
//日志 ,?+yu6eLb
public static void log(String sMsg) #4>F%_
{ XLT<,B}e
System.err.println(sMsg); mr? ii
} \mloR '
'>BHwc
r^)<Jy0|r
public static void log(int sMsg) =B1!em|
{ ;Lu|fQ#u*
System.err.println(sMsg); \BW(c)Q
} ! ZEKvW
} /_\4(vvf
/Y:Zqk3
q-#fuD^
/* p(Mv^ea
**TestMethod.java ;f Gi5=-
*/ ~4 ab\hq
package NetFox; c/RG1w
LJD"N#c
Y|F);XXIl
public class TestMethod { rH,N.H#]
]Ea-?IhD
OgX."pK
public TestMethod() ||f4f3R'
{ ///xx/weblogic60b2_win.exe RiklwR#~r/
try{ \N30SG?o
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?AE%N.rnsi
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UuGv= yC^6
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^&Bye?`5
fileFetch.start(); _17"T0
} x/~M=][tN
catch(Exception e){e.printStackTrace ();} 3-'|hb
~gN'";1i
aF:LL>H
} XJ"9D#"a>
q2y:bqLWl
V|= 1<v
public static void main(String[] args) .;'xm_Gw<
{ AO6;aT
new TestMethod(); F+GQl
} <S qbj;
} .JE7vPv%!
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