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%JAX>v&B
} x>+sqFd\
for(int i=0;i<nEndPos.length-1;i++) 2M)E1q|a
{ `yh][gqVE~
nEndPos = nStartPos[i+1]; q8MyEoc:n
} 3gYtu-1
nEndPos[nEndPos.length-1] = nFileLength; <?h(Dchq
} 1n[wk'}qf4
} a:s$[+'Y
@6*eS+t\
3zv0Nwb,
//启动子线程 *;T'=u_lR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &5*t*tI
for(int i=0;i<nStartPos.length;i++) *Ag3qnY
{ uK0L>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Nz:p(X!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vhzz(UPUt
nStartPos,nEndPos,i); pZ]&M@Ijp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w$j6!z
fileSplitterFetch.start(); SNf~%B?`L
} 89t"2|9 u
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gn4XVzB`O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9%2he)Yqc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (a"/cH
nEndPos = " + nFileLength); Jl|^^?
// fileSplitterFetch[nPos.length-1].start(); jI~$iDdOfs
c*i,z
T8^l}Y B
//等待子线程结束 &'Xgf!x
//int count = 0; wbI1~/
//是否结束while循环 ]Bs{9=2
boolean breakWhile = false; 3Kq/V_
V9cj
h-x~:$Z,
while(!bStop) x4,[5N"}YK
{ -j1]H"-
write_nPos(); _Ud!tK*H
Utility.sleep(500); Df$~=A}
breakWhile = true; A)&CI6(
w|NId,#f
0QyL}y2
for(int i=0;i<nStartPos.length;i++) *;Cpz[N
{ 3J8M0W
if(!fileSplitterFetch.bDownOver) /. H(&
{ OzR<jCOS
breakWhile = false; 2`A[<S
break; RL H!f1cta
} W$W w/mcl+
} Fl*<N
if(breakWhile) nWhf
break; hZWkw{c
eU.C<Tv:8
2B5Ez,'#x
//count++; o_5[}d
//if(count>4) n/e,jw
// siteStop(); $GHi9aj_P
} FF0~i+5
Ul3xeu
8L]Cc!~
System.err.println("文件下载结束！"); :B\$7+$v
} Z~[eG"6zI
catch(Exception e){e.printStackTrace ();} 4~8-^^
} TX7dwmt)N
sHPj_d#
"<f?.l\+
//获得文件长度 [+="I &
public long getFileSize() [.w`r>kZI
{ 5Zmc3&vRl
int nFileLength = -1; s#8T46?
try{ U#<{RqY
URL url = new URL(siteInfoBean.getSSiteURL()); |?hsMN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8k+k\V{
httpConnection.setRequestProperty("User-Agent","NetFox"); `b%^_@Fb
D *IeG>%
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int responseCode=httpConnection.getResponseCode(); @ZrNV*&<
if(responseCode>=400) Hs{x Z:
{ tu/4
processErrorCode(responseCode); j?g#8L;W\w
return -2; //-2 represent access is error QL2 `X2
} "xn,'`a
S~&9DQNj
8iM:ok
String sHeader; x(p/9$.#
m\E=I5*/
`cIeqp
for(int i=1;;i++) E,cQ9}/
{ yU"#2 *C
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); P% 8U
//Utility.log(in.readLine()); 3,#v0#
sHeader=httpConnection.getHeaderFieldKey(i); Ndyo)11z
if(sHeader!=null) E`{DX9^
{ ]z| 2
if(sHeader.equals("Content-Length")) MXjN./
{ K@/dQV%Z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )-Z*/uF^
break; Y kvEQ=
} :nfy=*M#
} rq\<zx]au
else UUa@7|x
break; K$B~vy6E`
} 66$hdT$
} DF'~ #G8
catch(IOException e){e.printStackTrace ();} 5+j):_
catch(Exception e){e.printStackTrace ();} &JD^\+7U:
Qz_4Ms<o
s OLjT34
Utility.log(nFileLength); UIU6rilB
8@|{n`n]
\< a^5'
return nFileLength; T)Q_dF.N
} "L8Hgwg
Ekh)l0 l
G({VK
//保存下载信息（文件指针位置） TI0=nfj
private void write_nPos() 4Lz[bI
{ ?FEh9l)d\
try{ oq b(w+<
output = new DataOutputStream(new FileOutputStream(tmpFile)); |KO[[4b ?+
output.writeInt(nStartPos.length); oa[O~z{~
for(int i=0;i<nStartPos.length;i++) "?FBbJ
{ VuN#j<H
// output.writeLong(nPos); NbCIL8f]
output.writeLong(fileSplitterFetch.nStartPos); P m&^rC;
output.writeLong(fileSplitterFetch.nEndPos); 5H|7DVG
} 6E(..fo:"
output.close(); _c-(T&u<
} 0%,?z`UY
catch(IOException e){e.printStackTrace ();} CkNh3'<wg
catch(Exception e){e.printStackTrace ();} @W~aoq6
} I :bT"N
#&?}h)Jr'
4r86@^c*
//读取保存的下载信息（文件指针位置） _'^_9u G
private void read_nPos() g_?Q3
{ )n[=)"rf
try{ DbtkWq%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6\.LG4@LO
int nCount = input.readInt(); \'|t>|zhp
nStartPos = new long[nCount]; n-,mC/4
nEndPos = new long[nCount]; &qIdT;^=I
for(int i=0;i<nStartPos.length;i++) fKtlfQG
{ txQr|\4k
nStartPos = input.readLong(); B(O6qWsL
nEndPos = input.readLong(); x5rLGt
} &l4kwds R
input.close(); L:Mjd47L
} -8dz`o}
catch(IOException e){e.printStackTrace ();} +rhBC V
catch(Exception e){e.printStackTrace ();} K}GRU)
} Prc1U)nfo
/x_AWnU
F IB)cpo
private void processErrorCode(int nErrorCode) Y]5MM:mI
{ `)MKCw$e
System.err.println("Error Code : " + nErrorCode); q!~DCv df
} ( )f)
Y^;izM}
z\?<j%e!t
//停止文件下载 rfzzMV
public void siteStop() +Hp`(^(
{ hF`<I.z}
bStop = true; 'tU\~3k
for(int i=0;i<nStartPos.length;i++) | h+vdE8
fileSplitterFetch.splitterStop(); `0MQL@B
!|- U,
zJ:%iL@
} xuVc1jJH
} 17 0r5
//负责部分文件的抓取 7#7|+%W0
**FileSplitterFetch.java rp2g./2
*/ !\O!Du
package NetFox; FJxb!-0&
mAJ'>^`^
H$pgzNL
import java.io.*; ?IoA;GBg
import java.net.*; mZuLwd$0
,WM-%2z^4I
lvNi/jk
public class FileSplitterFetch extends Thread { $xF[j9nM
_N>#/v)Yi
_+~&t9A!
String sURL; //File URL >hV2p/D
long nStartPos; //File Snippet Start Position VWzuV&;P
long nEndPos; //File Snippet End Position b):aqRwP
int nThreadID; //Thread's ID ;18u02z^
boolean bDownOver = false; //Downing is over /Ei e5p
boolean bStop = false; //Stop identical |2rOV&@l9
FileAccessI fileAccessI = null; //File Access interface 'C#[iRG4
k2PK4Ua_}q
Z)@[N 6\?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >ffC?5+
{ SZ7; } r8
this.sURL = sURL; Z+[W@5q
this.nStartPos = nStart; M-q5Jfm
this.nEndPos = nEnd; rw0s$~'
nThreadID = id; .j=mT[N,I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'op_GW
} ]<c\+9
.~q>e*8AH
/^bU8E&^M
public void run() n[# **s
{ 7VWy1
while(nStartPos < nEndPos && !bStop) V?p`rrj@
{ |`{$Ego:
i XGy*#>V
OPogH=vf
try{ rR#wbDr5
URL url = new URL(sURL); sB^ejH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?FV%e
httpConnection.setRequestProperty("User-Agent","NetFox"); A4b+:MQ*OX
String sProperty = "bytes="+nStartPos+"-"; Nw-U*y
httpConnection.setRequestProperty("RANGE",sProperty); ?1] \3nj
Utility.log(sProperty); U}5]Vm$]
D0TFC3.k}
dxtG3
InputStream input = httpConnection.getInputStream(); _sy]k A
//logResponseHead(httpConnection); up0=Y o@
>g@@ yR,
8s-X H
byte[] b = new byte[1024]; ~,xso0
int nRead; @U1t~f^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) P97i<pB Y_
{ *&R|0I{>
nStartPos += fileAccessI.write(b,0,nRead); aVr=7PeF
//if(nThreadID == 1) BqA_CW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |oe
} <E^;RG
wx!2/I>
9-24c
Utility.log("Thread " + nThreadID + " is over!"); 3a=\$x@
bDownOver = true; NmF8BmIj
//nPos = fileAccessI.write (b,0,nRead); .f>7a;V?}
} {eQijW2Z3
catch(Exception e){e.printStackTrace ();} lQm7`+
} 8LXK3D}?3
} )V*`(dn'zm
?U1Nm~'UZ
T1x67 b u
//打印回应的头信息 CJs ~!ww
public void logResponseHead(HttpURLConnection con) {G<1.
{ [qkc6sqo
for(int i=1;;i++) (XFF}~>B.
{ }nO%q6|\V
String header=con.getHeaderFieldKey(i); 2+g'ul`
if(header!=null) }jdmeD:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /~c9'38
Utility.log(header+" : "+con.getHeaderField(header)); W`TSR?4~t?
else `gJ$fTi&
break; RUVrX`u*(
} <p2\;\?4z
} l7IF9b$c
2pP"dX
k5+ Fxf
public void splitterStop() t'.:"H8BI
{ }9;mtMR$
bStop = true; VRSBf;?
} bMv[.Z@v(
\%V !& !'
S?OCy4dk:
} Z/4bxO=m
"s(|pQh;
~lqNWL^l
/* j7NOYm5N
**FileAccess.java Z J1@z.
*//文件访问(定位，写) >!tfvM2X{
package NetFox; kV!1k<f
import java.io.*; 0I2?fz)
4p6T0II_$
;z+}|>!
public class FileAccessI implements Serializable{ R9QW%!:,\2
-mLu!32I<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'UZ i>Ta
RandomAccessFile oSavedFile; $*Wa A`(U
long nPos; Y@T$O<*
'0&HkM{ D
HsT6 #K
public FileAccessI() throws IOException %kgT=<E'
{ j_0l'Saj
this("",0); m#RMd,'X
} N$.ls48a4-
7;]IlR6
M8y|Lm}o
public FileAccessI(String sName,long nPos) throws IOException 1(%6X*z
{ Ub4)x
oSavedFile = new RandomAccessFile(sName,"rw"); 8H8Q
this.nPos = nPos; \]\h,Y8
oSavedFile.seek(nPos); ?`6Mfpvj96
} /BhP`a%2Q
'GO*6$/
Ke~!1S8=
public synchronized int write(byte[] b,int nStart,int nLen) ZZfi,0R
{ N.SV*G @
int n = -1; #c'}_s2F[
try{ =2vZqGO30
oSavedFile.write(b,nStart,nLen); lh!8u<yv*
n = nLen; [TxvZq*4
} .SSPJY(
catch(IOException e) HL:w*8a
{ Z1;+a+S=z
e.printStackTrace (); `FX?P`\@I
} u^x<xw6f
M*~XpT3
=CCddLO
return n; mJH4M9WJ]
} [[]NnWJ
+ EKp*Vje
6{fo.M?
} z(>:LX"xz
<7/7+_y
.t{uzDM
/* N%u4uLP5k
**SiteInfoBean.java 7ks!0``
*/ .E{FD%U
package NetFox; C/ ]Bx
;$qc@)Uwp
AU9:Gu@M/
public class SiteInfoBean { '[HU!8F
n:H |=SF{
%z"$?Iv
private String sSiteURL; //Site's URL N~S#(.}[
private String sFilePath; //Saved File's Path 5p3:8G7
private String sFileName; //Saved File's Name q>6,g>I
private int nSplitter; //Count of Splited Downloading File dKw[#(m5v
%uo#<Ny/ I
c^5fhmlt
public SiteInfoBean() twaH20
{//nSplitter的缺省值为5 2&AX_#P
//default value of nSplitter is 5 P;|63"U
this("","","",5); !L/.[:X
} (+BrC`
f;&XTF5D^
6r[pOl:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) xZloEfv.B
{ U-{3HHA
sSiteURL= sURL; '}F9f?
sFilePath = sPath; m]{/5L
sFileName = sName; ^lK!tOeO
this.nSplitter = nSpiltter; yC!>7@m
D?H|O[
Us>
} +|4olK$[
4~WSIR-
zXwdU58
public String getSSiteURL() ,.Lo)[(
{ PX?^v8wlqL
return sSiteURL; ]a:T]x6'
} iA'p!l|P
'p%w_VbI
=H}}dC<)
public void setSSiteURL(String value) YC*`n3D|'
{ !Uhcjfq`e
sSiteURL = value; X-j<fX_
} y35e3
CdtwR0
^6!8)7b
public String getSFilePath() Lr`Gyl62
{ wvr`~e
return sFilePath; |I.5]r-EK
} GB6(WAmr
+>%AG&Pc
oiz]Bd
public void setSFilePath(String value) ;b_<5S
{ vgr5j
sFilePath = value; \,I{*!hw
} a3He-76
Q"oJhxS
}MM:qR
public String getSFileName() 1O90 ]c0
{ fECmELd
return sFileName; |CBJ8],mT
} KF`mOSP
hm1.UE
;*20b@
public void setSFileName(String value) #vPk XcP
{ grJ(z)c
sFileName = value; w&&)v~Y_
} 2k`Q+[?{q>
XKT[8o<L
M%Q_;\?]
public int getNSplitter() i \.&8
{ ^4{{ +G)j
return nSplitter; 5ai$W`6
} tZr_{F@
^j?"0|
~y ?v
public void setNSplitter(int nCount) \@6V{y'Zo
{ \Fu(IuD
nSplitter = nCount; JS&;7Z$KX
} 1_G+sDw$
} |j$$0N
8: VRq
~jC$C2A0
/* &Hl w2^
**Utility.java ZP.~Y;Ch;-
*/ +n|@'= ]
package NetFox; tYUo;V
.B6mvb\
2y9$ k\<xV
public class Utility { qp/nWGj
P_ b8_ydU
#5^S@}e
public Utility() >V&GL{
{ <?!%dV{z
z,SNJIsx
F Zk[w>{
} 3X1 U
h;J%Z!Rjw
//线程睡眠 Oc/ i'
public static void sleep(int nSecond) F[0w*i&u5
{ z+nq<%"'
try{ SCq3Kh
Thread.sleep(nSecond); ZVCa0Km
} D#X&gE
catch(Exception e) (i]0IYMXy*
{ z+Ej`$E{lD
e.printStackTrace (); {=P}c:iW
} iDlg>UYd
} kM(,8j
0-Wv$o[
//日志 v&"sTcS|
public static void log(String sMsg) tSunO-\y
{ V:1_k"zQ
System.err.println(sMsg); :U'Oc3l#Y
} c+UZ UgP
~fz9PoC
RM!VAFH
public static void log(int sMsg) WAb@d=H{+>
{ e]7J_9t@
System.err.println(sMsg); ov'C0e+o
} twql)lbx
} W0# VDe]>
R^6^{q
K`kWfPwp
/* .wcKG9u
**TestMethod.java q>VvXUyK,
*/ 3O?[Yhk`.
package NetFox; 51!#m|
<+ckE2j
5Ja[p~^L
public class TestMethod { G2FD'Sf
2L7ogyrU/A
-qDL':
public TestMethod() W_|7hwr
{ ///xx/weblogic60b2_win.exe k FE<M6a9@
try{ J-~:W~Qx4N
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u%nhQ%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $_ k:{?
SiteFileFetch fileFetch = new SiteFileFetch(bean); WNiM&iU
fileFetch.start(); W%K=N-kE_
} ?qczMck_
catch(Exception e){e.printStackTrace ();} |Q#CQz
6b h.5|
e|.a%,Dcy
} *l-F
++d[YhO
qk!,:T
public static void main(String[] args) S~.%G)R
{ :ZU-Vi.b
new TestMethod(); tL S$D-
} -KiI&Q
} O[HBw~
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