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)); 1HG~}E
} v!T%xUb0
for(int i=0;i<nEndPos.length-1;i++) V&<vRIsN
{ zRdL-u%(#
nEndPos = nStartPos[i+1]; 3'6%P_S
} TU{^/-l
nEndPos[nEndPos.length-1] = nFileLength; Y 9]
} D)XF@z;
} o ^L3Xiv
1u7Kc'.xc
"qUUH4mR`
//启动子线程 y^tuybpZY<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Qx|m{1~-
for(int i=0;i<nStartPos.length;i++) <Yu}7klJE
{ x):cirwkl
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ";yCo0*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7udMF3;>
nStartPos,nEndPos,i); Vm6G5QwM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H#x=eDU|k
fileSplitterFetch.start(); @dQIl#
} I.TdYSB
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >4`("#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); XtVx H4q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l=U@j T
nEndPos = " + nFileLength); 1GKd*z
// fileSplitterFetch[nPos.length-1].start(); [!p>Id
-?`^^v
cq+|fg~Yy
//等待子线程结束 6Y0k}+j|>E
//int count = 0; @6 uB78U4O
//是否结束while循环 k'{'6JR
boolean breakWhile = false; .ml24SeC
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while(!bStop) R9nW5f Nf
{ -hw^3Af
write_nPos(); ya3A^&:
Utility.sleep(500); bmVksi2b
breakWhile = true; 0gw0
nS)U+q-x&o
js)M c*]&
for(int i=0;i<nStartPos.length;i++) %719h>$
{ -jdS8n4
if(!fileSplitterFetch.bDownOver) HtB>#`'
{ 0]=|3-n
breakWhile = false; -iWt~
break; K>X#,lE-
} Ac}+Uq
} M_*"g>Z
if(breakWhile) _0ki19rs
break; Z .VIb|
3maiBAOKz
UXwnE@`F
//count++; mH2XwA|
//if(count>4) Tt#4dm-
// siteStop(); 0>Iy`>]
} G vMhgG=D
F7lhLly
SYd4 3PA
System.err.println("文件下载结束！"); :UM>`Y
} d\dh"/_$
catch(Exception e){e.printStackTrace ();} ]W39HL
} $q,2VH:Ip
$(B|$e^:(
^N#B(F
//获得文件长度 >Q#h,x~vu
public long getFileSize() Wsya:9|
{ 0w9)#e+JS
int nFileLength = -1; TELN4*
try{ <5(P4cm9
URL url = new URL(siteInfoBean.getSSiteURL()); ")m0{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p&dpDJ?d:=
httpConnection.setRequestProperty("User-Agent","NetFox"); VWf&F`^B(
dPZrX{ c
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int responseCode=httpConnection.getResponseCode(); 5e=9~].7
if(responseCode>=400) S?ELFq(g
{ 3y?I^ .B
processErrorCode(responseCode); 4{4VC"fa
return -2; //-2 represent access is error cB#5LXbCE
} *P2_l Q=
y(/"DUx
Kab"r_'
String sHeader; Qc1NLU9:
KSkT6_<
0N.B=j|
for(int i=1;;i++) pFb}5Q
{ j<|I@0
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); VbX+`CwH
//Utility.log(in.readLine()); [w*YH5kX
sHeader=httpConnection.getHeaderFieldKey(i); art L
if(sHeader!=null) LkYcAY$w
{ Ug(;\*yg
if(sHeader.equals("Content-Length")) A)6xEeyR
{ (%.[MilxPM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L~9Q7 6w
break; QS(aA*D
} ;PM(q<@\
} -Uj)6PzGu
else ?5'EP|<
break; SR)jJ=R3
} mQ(6ahD U
} S&(MR%".
catch(IOException e){e.printStackTrace ();} $>^DkrOd
catch(Exception e){e.printStackTrace ();} %S*<2F9
e=uElp'%
C:z+8wt
Utility.log(nFileLength); ybk~m
t<=Ru*p
?RW7TWf
return nFileLength; A#NJ8_
} %-9?rOr
n!Hj4~T0
Z*uv~0a>9Q
//保存下载信息（文件指针位置） I_hus
private void write_nPos() Z[9) hGh
{ AzFd#P
try{ 8(d Hn
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ub[SUeBGH
output.writeInt(nStartPos.length); 7\(mn$
for(int i=0;i<nStartPos.length;i++) Vx'82CIC
{ :\hcl&W:
// output.writeLong(nPos); j'L/eps?S
output.writeLong(fileSplitterFetch.nStartPos); vVvx g0
output.writeLong(fileSplitterFetch.nEndPos); ?X $#J'U;
} l$[7pM[
output.close(); @QOlo-u
} 1f}YKT
catch(IOException e){e.printStackTrace ();} ZVu_E.4.
catch(Exception e){e.printStackTrace ();} QjT$.pUd
} f6/<lSoW
.,({&L
R:N4_4& C~
//读取保存的下载信息（文件指针位置） d `MTc
private void read_nPos() J!{"^^*
{ GgT 5'e;N
try{ b"4'*<=au
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); '%Fg+cZN\
int nCount = input.readInt(); t+9[ki
nStartPos = new long[nCount]; -d-vzri
nEndPos = new long[nCount]; h2S!<
for(int i=0;i<nStartPos.length;i++) TA4>12C6
{ 5:R$xgc
nStartPos = input.readLong(); UTWchh
nEndPos = input.readLong(); Tumv0=q4wd
} "mk@p=d
input.close(); gm^j8B
} 6DkFIkS
catch(IOException e){e.printStackTrace ();} "FD`1
catch(Exception e){e.printStackTrace ();} \p4>onGI
} @ra^0
1>yh`Bp\=
hZZ
private void processErrorCode(int nErrorCode) 5S9i>B
{ T6ihEb$C
System.err.println("Error Code : " + nErrorCode); ^Uq%-a
} mV>l`&K=
we("#s1=
'@0Z#A
//停止文件下载 isBtJ7\Sc
public void siteStop() Bm>>-nG;
{ xF8U )j!
bStop = true; d/&W[jJ
for(int i=0;i<nStartPos.length;i++) \=1$$EDS9
fileSplitterFetch.splitterStop(); s!IX3rz
s7d4)A%
B3^F $6=
} ?2(52?cJ
} omP\qOc
//负责部分文件的抓取 @1w[~QlV
**FileSplitterFetch.java XJZ\ss
*/ ?td`*n~,
package NetFox; @> |3d
&xWej2a!
#}p@+rkg2
import java.io.*; N%f% U
import java.net.*; n 9>**&5L
G'U! #
V?L8BRnV
public class FileSplitterFetch extends Thread { "M;aNi^B
1fH2obI~X
8@ZZ[9kt
String sURL; //File URL ?W 6 :$
long nStartPos; //File Snippet Start Position Qx")D?u
long nEndPos; //File Snippet End Position @?2ES@G+Ji
int nThreadID; //Thread's ID )FdS;]
boolean bDownOver = false; //Downing is over )Fsc0_
boolean bStop = false; //Stop identical Te6cw+6
FileAccessI fileAccessI = null; //File Access interface tE8aL{<R
]5O]=^ u0
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @=ro/.
{ eF"k"Ckt'
this.sURL = sURL; WR"?j9y_q
this.nStartPos = nStart; B"Ma<"HU
this.nEndPos = nEnd; M!wa }
nThreadID = id; drQI@sPp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .fgVzDR|+
} [C#H _y(
r!<)CT}D
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public void run() ID]E3K
{ vbh 5
while(nStartPos < nEndPos && !bStop) $5wf{iZY.Q
{ ew.jsa`TrW
Kh8
@tIY%;Bgk
try{ ;Rf@S$
URL url = new URL(sURL); s'^sT=b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HfPu~P
httpConnection.setRequestProperty("User-Agent","NetFox"); ^]NFr*'!
String sProperty = "bytes="+nStartPos+"-"; JKz]fgOd$
httpConnection.setRequestProperty("RANGE",sProperty); X \BxRgl},
Utility.log(sProperty); 50CjH"3PZ`
6b1AIs8
bOolBKV
InputStream input = httpConnection.getInputStream(); vlqL
//logResponseHead(httpConnection); 7'!DK;=TD6
Z8ds`KZM
x~JOg57up
byte[] b = new byte[1024]; ~f:"Q(f+
int nRead; +>ld
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =[:pm)
{ _+9o'<#u(
nStartPos += fileAccessI.write(b,0,nRead); >}E
//if(nThreadID == 1) G3o`\4p
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n52Q-6H
} $jOp:R&I^3
?[=OQ/E
?="?)t[
Utility.log("Thread " + nThreadID + " is over!"); ZY|$[>X!
bDownOver = true; W)<t7q+
//nPos = fileAccessI.write (b,0,nRead); $-p9cyk
} feJl[3@tO
catch(Exception e){e.printStackTrace ();} !'#GdRstv
} @\WeI"^F8
} ||))gI`3a
#}lWM%9Dy
<Gna}ALkg
//打印回应的头信息 Vb)NWXmyu
public void logResponseHead(HttpURLConnection con) aL&nD1f=!-
{ ,1B`Ve
for(int i=1;;i++) jp7cPpk:LG
{ NRT@"3,1YP
String header=con.getHeaderFieldKey(i); z?@N+||,.
if(header!=null) Nt|Fw$3*5{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *\Lr]6k
Utility.log(header+" : "+con.getHeaderField(header)); ffMk.SqI
else F/cA tT.M?
break; -wr_x<7
} g`w46X
} iwy;9x
.^6yCs5~`
:'FCeS9
public void splitterStop() DP-0,Gt&Xj
{ )b1X6w[
bStop = true; J$U_/b.mk
} \YSprXe
1H?I?IT30
w*]FJ-b<.j
} HQNpf1=D
[tRb{JsUd
~RH)iI
/* &xpvHKJl
**FileAccess.java ,n2"N5{jw
*//文件访问(定位，写) "A> _U<Y
package NetFox; \ B'AXv6
import java.io.*; G+&pq
e$Mvl=NYp\
?r{hrAx
public class FileAccessI implements Serializable{ k=cDPu -
pqTaN=R8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R9Y@I
RandomAccessFile oSavedFile; ];'7~",Y
long nPos; z8XWp[K
{.?pl]Zl6
dvM%" k
public FileAccessI() throws IOException phQ{<wzwp
{ s\< @v7A
this("",0); FKPR;H8>
} *I[tIO\
:H:Se
aU@1j;se@
public FileAccessI(String sName,long nPos) throws IOException E $P?%<o
{ ]V)*WP#a
oSavedFile = new RandomAccessFile(sName,"rw"); #q>\6} )
this.nPos = nPos; ^X?uAX-RP|
oSavedFile.seek(nPos); "lrQC`?
} ^ FM
7?D?s!%\
>=:^N-a
public synchronized int write(byte[] b,int nStart,int nLen) _Ie:!q
{ sm;kg=
int n = -1; H@u5&
try{ e,r7UtjoxR
oSavedFile.write(b,nStart,nLen); s7sTY
n = nLen; a`[9<AM1#
} {5fL!`6w
catch(IOException e) O~v~s 'c&
{ [k0/ZfFwV
e.printStackTrace (); vvu $8n
} tLxeq?Oo]
Wffz&pR8
&E1m{gB(
return n; Y;'SD{On
} $}'(%\7"
Zu<S<??Jf
$ai;8)C6
} 5^R?+<rd
X7[gfKGL)N
$$uMu{?0i
/* M%Ksyr9
**SiteInfoBean.java vt nT
*/ CZ'm|^S
package NetFox; I~6 o<HO
$4}G
'kco. 1{
public class SiteInfoBean { "$aoIXv
B,&QI&k`~
($>m]|
private String sSiteURL; //Site's URL $7ix(WL<%
private String sFilePath; //Saved File's Path lD, ~%
private String sFileName; //Saved File's Name =LODX29
private int nSplitter; //Count of Splited Downloading File I!Z"X&
i(OeE"YA
6B% h
public SiteInfoBean() G%, RD}D
{//nSplitter的缺省值为5 z[ 'G"yCi
//default value of nSplitter is 5 $PI9vyS
this("","","",5); YRCs&tgs
} mU~&oU
nI&p.i6
,tcUJ}l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 89;@#9
{ 6Ol9P56j
sSiteURL= sURL; =Xg/[J%
sFilePath = sPath; ,p OGT71
sFileName = sName; 3Pllxq<n
this.nSplitter = nSpiltter; K[ [6A:
%q~q,=H$]
fm`V2'Rm
} A)V*faD
01n132k
Aq*?Q/pV
public String getSSiteURL() :enR8MS
{ <9piKtb|L
return sSiteURL; lSW'qgh
} f$6N
h6OQeZ.
]@ke_' "
public void setSSiteURL(String value) i;U*Y *f
{ "M!m-]
sSiteURL = value; _ilitwRN3
} UAT\ .
9cUa@;*1
$A-X3d;'\/
public String getSFilePath() |/^S%t6*
{ gBi3^GxjM?
return sFilePath; 9Li*L&B)
} =>B"j`oR
w$AR
KYtCN+vsG
public void setSFilePath(String value) C}pm>(F~
{ <R;wa@a>
sFilePath = value; M?UUT8,
} 'j<u0'K@
<n06(9BF
Btm_S\1
public String getSFileName() DKu$u]Z
{ 'QxJU$
return sFileName; 7U_ob"`JV
} bT&{8a
w5{l-Z
%),u0:go
public void setSFileName(String value) !C05;x8{
{ Zfcf?&><
sFileName = value; MTZCI}
} Z#-N$%^F
kx?Yin8K
MO0NNVVi%U
public int getNSplitter() Y`(Ri-U4
{ 77yYdil^W+
return nSplitter; iiMS3ueF
} )=d)j^t9
nEd "~
R"V90bCf
public void setNSplitter(int nCount) *bf 5A9
{ <{Y3}Q
nSplitter = nCount; NRJp8G Z%U
} ]6[+tpx
} 3CjixXaA$
aG^E^^Y
v9-4yZU^WR
/* tEvDAI} 5
**Utility.java 7~XA92
*/ vm_]X{80;
package NetFox; t_w\k_ T
-43>?m/a
B I)@n:p
public class Utility { U364'O8_
m^!j)\sM5
ufIvvZ*
public Utility() BJWlx*U]
{ 9!Q ZuZY
qe{;EH*
4RB%r
} gM>?w{!LBx
4Ii5V c
//线程睡眠 '(3 QyCD
public static void sleep(int nSecond) P@ew' JL%
{ 7$Z_'GJ]1C
try{ 5(J?C-Pk
Thread.sleep(nSecond); D^6iQW+.P
} g/!MEOVx
catch(Exception e) V~j^
{ OxGfLeP.R!
e.printStackTrace (); >fI\f <ez
} UWC4PWL,>C
} >_ZEQC
p03I&d@w>
//日志 ;Y;r%DJ
public static void log(String sMsg) I<D7Jj
{ vLHn4>J,R
System.err.println(sMsg); qS@3:R
} tm.60udbo
{{Ox%Zm
3=sBe HL
public static void log(int sMsg) k+-?b(z)$
{ {c9 fv H
System.err.println(sMsg); #J&3Zds
} 5tpC$4m
} AZc=Bbh
By8SRWs
;!S5P(
/* #0b:5.vy
**TestMethod.java X/2GTU7?
*/ 8Lx/ZGy
package NetFox; VfpT5W<
B._YT
r/'!#7dLG-
public class TestMethod { |{kbc0*
~k"b"+2
ial{A6X
public TestMethod() 4x[_lsj
{ ///xx/weblogic60b2_win.exe wB0vpt5f
try{ \z.bORy
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~:7y!=8#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j [lS.Lb
SiteFileFetch fileFetch = new SiteFileFetch(bean); ub~ t}
fileFetch.start(); ^.8~}TT-U
} A1+:y,wXs
catch(Exception e){e.printStackTrace ();} A(E}2iP9=
G)I` M4}*n
}6-olVg
} d=^QK{8
,H+Y1N4W(
U[x$QG6m!
public static void main(String[] args) Eej Lso#\
{ ]#f%Dku.m
new TestMethod(); ljZRz$y
} 4E5;wH
} M{G}-QK_.
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