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)); :at$HCaK
} zNIsf"
for(int i=0;i<nEndPos.length-1;i++) 1SR+m>pL
{ r}jGUe}d
nEndPos = nStartPos[i+1]; k0Uyf~p~
} !H}vu]R
nEndPos[nEndPos.length-1] = nFileLength; iV eC=^1
} .3MIcj=p
} /\WQxe
<0PT"ij
,.qMEMm
//启动子线程 r9ww.PpNk#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; f?'JAC*
for(int i=0;i<nStartPos.length;i++) wV^V]c?U
{ m2v'WY5u
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |\g5+fv9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), a!u rew#
nStartPos,nEndPos,i); j<)9dEM'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); INyk3`FT
fileSplitterFetch.start(); g'|MA~4yB
} 3dRr/Ilc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :bC40@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); eR3$i)5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R]i7 $}n
nEndPos = " + nFileLength); x4/M}%h!;B
// fileSplitterFetch[nPos.length-1].start(); 4X*>H
HVC>9_:]
PK4iuU`vh
//等待子线程结束 ]TyisaT
//int count = 0; &JtV'@>v
//是否结束while循环 ^tCd L@$AS
boolean breakWhile = false; ]C:l,I
<&:=z?30"
h`H,a7
while(!bStop) +fnK/%b
{ V.{H9n]IO
write_nPos(); ;jipe3LU
Utility.sleep(500); J:kmqk!
breakWhile = true; \l@,B +)
w-0mzk"
q=9`06
for(int i=0;i<nStartPos.length;i++) {pHM},WJ
{ dS5a
if(!fileSplitterFetch.bDownOver) l}lIi8
{ RJ$7XCY%`*
breakWhile = false; Y}vr>\
break; gB4U*D0[e~
} +a*^{l}AST
} (S v~2
if(breakWhile) $&2UTczp
break; j8sH#b7Z
/-i!;!
6HlePTf8
//count++; ,yTjU{<"
//if(count>4) <fs2fTUeqF
// siteStop(); s\P2Bp_{
} 2^^=iU=!<|
d`/tE?Gw
G7CG~:3h+
System.err.println("文件下载结束！"); zH*KYB
} %zOh
catch(Exception e){e.printStackTrace ();} d%0~c'D8a
} MX ;J5(Ae
FEJ~k1z
EMc;^ d
//获得文件长度 DK oN}c
public long getFileSize() "kA*Vc#
{ m-jHze`D3
int nFileLength = -1; E~AjK'Z
try{ D91e\|]
URL url = new URL(siteInfoBean.getSSiteURL()); 3q?\r` a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T]?n)L,2
httpConnection.setRequestProperty("User-Agent","NetFox"); "hy.GWF|*
0pSmj2/,.
@GvztVYo
int responseCode=httpConnection.getResponseCode(); Z*FrB58
if(responseCode>=400) K_ci_g":
{ C*G=cs\i
processErrorCode(responseCode); U.@*`Fg
return -2; //-2 represent access is error i>joT><B
} @e'5E^
RAp=s
/P 2[:[w
String sHeader; )<xypDQ
&< !Ufa&
2r6'O6v
for(int i=1;;i++) A'%1ZQ33O
{ hbcuK&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "C*B,D*}:
//Utility.log(in.readLine()); w`DW(hXJ
sHeader=httpConnection.getHeaderFieldKey(i); bUY>st'
if(sHeader!=null) `w.AQ?p@
{ {Ixg2=E\
if(sHeader.equals("Content-Length")) X7g3
{ 8Mbeg ,P
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I=!rbF;Z
break; mB0l "# F
} 1U,1)<z~u
} QL$S4 J"
else %xQ.7~
break; .WQ+AE8Q
} oQL59XOT4
} 8+Td-\IMk
catch(IOException e){e.printStackTrace ();} 2z@\R@F
catch(Exception e){e.printStackTrace ();} 4);)@&0Md~
B7Tk4q\;Q
. ]8E7
Utility.log(nFileLength); n\ Hs@.
>~\89E02
MJ\eh>v&
return nFileLength; %riK+
} k'PQ} ,Vb
3.)b4T
o#[ KS:Y
//保存下载信息（文件指针位置） Q_vW3xz
private void write_nPos() w%zRHf8C
{ :>81BuMvg
try{ nL?oTze*p
output = new DataOutputStream(new FileOutputStream(tmpFile)); H-p;6C<
output.writeInt(nStartPos.length); K)_WL]RJ.4
for(int i=0;i<nStartPos.length;i++) 9V.u-^o&
{ \`w4|T
// output.writeLong(nPos); u(!&:A9JFd
output.writeLong(fileSplitterFetch.nStartPos); oW;6h.
output.writeLong(fileSplitterFetch.nEndPos); ]LZ`LL'#Y_
} k;5Pom
output.close(); o-cAG{.WC
} g_Im;1$
catch(IOException e){e.printStackTrace ();} =@)d5^<5F
catch(Exception e){e.printStackTrace ();} wIf {6z{
} ,]5Ic.};p
_xLHrT!y
Y+qQIMZ
//读取保存的下载信息（文件指针位置） =\{\g7
private void read_nPos() j8K,jZ
{ Xo{`]
try{ #*>E*#?t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ! <WBCclX
int nCount = input.readInt(); ,Os? f:Y6
nStartPos = new long[nCount]; 7zTqNnPnf
nEndPos = new long[nCount]; p*l$Wj
for(int i=0;i<nStartPos.length;i++) F6hmku>\1
{ A!63p$VT;
nStartPos = input.readLong(); )J(q49
nEndPos = input.readLong(); .4l/_4,s_
} #Z~C`n u
input.close(); %5\3Aw
} [= "r<W0
catch(IOException e){e.printStackTrace ();} %/.a]j!
catch(Exception e){e.printStackTrace ();} ,pBh`av
} T$=4O9G
Q7bq
pA4*bO+
private void processErrorCode(int nErrorCode) ]h9!ei [
{ QjPj[c
System.err.println("Error Code : " + nErrorCode); $t-n'Qh^2
} jtm?z c
]8;n{ }X
N:"C+a(
//停止文件下载 ~}DQT>7$
public void siteStop() >`jU`bR@
{ T5O _LCIws
bStop = true; NcM>{{8
for(int i=0;i<nStartPos.length;i++) bY~@}gC**@
fileSplitterFetch.splitterStop(); rx:z#"?I
bqx0d=Z~[
l?*r5[O>n
} OJ4SbI
} Wn|&cG9
//负责部分文件的抓取 iK_c.b
**FileSplitterFetch.java 5y4u5Tm-%
*/ y/c%+Ca/
package NetFox; kWj \x|E
,572n[-q
X%9*O[6{
import java.io.*; 4FMAz^
import java.net.*; i.1U|Pi
DDd|T;8
StYzGJ
public class FileSplitterFetch extends Thread { VK3it3FI>3
o5aLUWi-
c3 &m9zC
String sURL; //File URL SNT5Amz!
long nStartPos; //File Snippet Start Position T{vR,
long nEndPos; //File Snippet End Position iwY'4Z e
int nThreadID; //Thread's ID YW; Hk1
boolean bDownOver = false; //Downing is over N6Z{BLZ
boolean bStop = false; //Stop identical P|jF6?C
FileAccessI fileAccessI = null; //File Access interface vs&8wbS)
_U)%kY8
iz]rFNR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rSVgWr8
{ !Ngw\@f
this.sURL = sURL; KbxR Lx]w
this.nStartPos = nStart; xU9@$am
this.nEndPos = nEnd; H]#Rg`~n
nThreadID = id; 5c-N0@\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (S^ck%]]a!
} EqM;LgE=
F:37MUQi
2)/NFZ
public void run() g\M5:Qm
{ `^U&#K
while(nStartPos < nEndPos && !bStop) XT@Mzo49z\
{ '7Ig.K&
}{],GHCjQ
G\iyJSj[P
try{ G{ mC7@
URL url = new URL(sURL); v vE\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `3iQZui
httpConnection.setRequestProperty("User-Agent","NetFox"); 1x >iz `A
String sProperty = "bytes="+nStartPos+"-"; KhM.Tc
httpConnection.setRequestProperty("RANGE",sProperty); :]eb<J
Utility.log(sProperty); QYThW7S
~S(^T9R
mgkyC5)d
InputStream input = httpConnection.getInputStream(); pvXcLR)L+3
//logResponseHead(httpConnection); ^i_Iqph=
{8NwFN.
3#.\
byte[] b = new byte[1024]; XrN- 2HTV
int nRead; ms~8QL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :mv`\
{ _dU P7H (
nStartPos += fileAccessI.write(b,0,nRead); Nf?\AK!
//if(nThreadID == 1) LAZVW</
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [>w%CY<Fd
} 5 d ;|=K
r[HT9
w+f=RHX"{
Utility.log("Thread " + nThreadID + " is over!"); O]nT>;PXX
bDownOver = true; E8/rZ~0O~
//nPos = fileAccessI.write (b,0,nRead); ehOs9b
} ^b53}f8H
catch(Exception e){e.printStackTrace ();} xFsmf<Vm
} %cW;}Y[?P
} J4yt N3
QB1M3b
Q_}/ Pn$1
//打印回应的头信息 ; Zq/eiB
public void logResponseHead(HttpURLConnection con) }e=e",eAT
{ zLek&s&-
for(int i=1;;i++) C+l?k2
{ HZ\k-!2
String header=con.getHeaderFieldKey(i); ~b8a^6:R"
if(header!=null) ]C *10S`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q\#UWsN(T/
Utility.log(header+" : "+con.getHeaderField(header)); `fW{yb
else \p6 }
break; v["3
} wOHEv^,
} :t2B^})\
/PC`0/b
#%cR%Z
public void splitterStop() jzrt7p*k}
{ 6An{3"
bStop = true; `$-lL"
} RG?MRxC
rl|Q)A{
ahp1!=Z-=
} u33zceE8
K^ 6+Ily
@+dHF0aXd
/* p\+6"28{_~
**FileAccess.java pF='jj51
*//文件访问(定位，写) pbdF]>\
package NetFox; #`j][F@N
import java.io.*; 2nx9#B*/T
vPsq<l}
L<)Z>@fR
public class FileAccessI implements Serializable{ }jcIDiSu
Opry`}5h
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (rMZ
RandomAccessFile oSavedFile; 2f`xHI/@fj
long nPos; >a9l>9fyY
73pC
[|<EDR
public FileAccessI() throws IOException yjeL9:jH[
{ .93S>U<_
this("",0); YOKR//|3
} ,TJ/3_lH
^^ j/
h60\ Y 8
public FileAccessI(String sName,long nPos) throws IOException DvJB59:_}
{ M8Juykw
oSavedFile = new RandomAccessFile(sName,"rw"); s*+ZYPk
this.nPos = nPos; 2+&R"#I
oSavedFile.seek(nPos); .~22^k
} )rbc;{.
9,KVBO
{]@Qu"M
public synchronized int write(byte[] b,int nStart,int nLen) kDg{>mf
{ <THUsY`3P&
int n = -1; H8<m9zDvl
try{ NlMQHma
oSavedFile.write(b,nStart,nLen); s+N^PX3
n = nLen; tgfM:kzw
} 1{7_ `[
catch(IOException e) L77EbP`P
{ }JH`'&3
e.printStackTrace (); v0u\xX[H;
} {NY]L==H
8k%H[Smn:
"&Ff[O*
return n; G ;jF9i
} 5{HtJ?sKc5
-P*xyI
p/4S$ j#Tn
} \ bC}&Iz6
sD.6"w7}
.oEFX8
/* "u,sRbL
**SiteInfoBean.java <gR`)YF7
*/ ~X[S<Gi#
package NetFox; V!H(;Tuuo
6,a%&1_
z,M'Tr.1|
public class SiteInfoBean { v<%]XHN
|zT%$
Mo~ki"9.
private String sSiteURL; //Site's URL ?C FS}v
private String sFilePath; //Saved File's Path (}sDm~;s
private String sFileName; //Saved File's Name Wf_CR(
private int nSplitter; //Count of Splited Downloading File { _-wG3f|
m&,bC)}
#i@ACAgn;6
public SiteInfoBean() zLo;.X[Y
{//nSplitter的缺省值为5 }z8{B3K
//default value of nSplitter is 5 vT&j{2U7XW
this("","","",5); w<v1N
} uSH>$;a
aX:#'eDB
i1tVdbC]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) umqLKf=x!
{ `:V}1ioX5
sSiteURL= sURL; 4,gol?a
sFilePath = sPath; {(_B
sFileName = sName; 4c
this.nSplitter = nSpiltter; VjC*(6<Gj
.@fK;/OuC
vU?b"n
} P"oYC$
mJSK; @w<O
Fecx';_1`
public String getSSiteURL() a|8|@,
{ r9+E'\
return sSiteURL; w:ORmR.p
} F\o;t:
E]e,cd
X!HDj<
public void setSSiteURL(String value) @^'G&%j
{ (Nm}3p
sSiteURL = value; S`ax*`
} 6F@zCv"w
$&ex\_W
^2C0oX
public String getSFilePath() pg}~vb"
{ UOn!Y@
return sFilePath; BM|-GErE
} I{`KKui<M
*p""YEN
83{x"G3>
public void setSFilePath(String value) $ /}:P
{ X{5v?4wI
sFilePath = value; ~AEqfIx*^&
} [ c ~LY4:
h5LJijJ
f}L>&^I)
public String getSFileName() 2neF<H?^o
{ \e`6=Q%
return sFileName; r24\DvS
} A6@+gP<
)ZS:gD
<Cf7E
public void setSFileName(String value) ;J,,f1Vw
{ ]7#^])>
sFileName = value; OhSt6&+
} iFAoAw(
"-0pz\a
gt2>nTJz.Z
public int getNSplitter() b9W<1eqF
{ V\iIvBpWg
return nSplitter; j6&zRFX
} n.Ur-ot
9J-!o]f .b
/{eih]`x(
public void setNSplitter(int nCount) ;[WSf{k
{ oW yN:Qh
nSplitter = nCount; 6nY )D6$JG
} ]X>QLD0W
} Q70**qm
zVc7q7E
eI/\I:G{f
/* }\PE {
**Utility.java eB(S+p?
*/ ?c=R"Yg$
package NetFox; 'y+bx?3Z
J^s<x#C
O5G<O(,\
public class Utility { RAD4q"}k
8ACYuN\
@MlU!oR&
public Utility() W[1f]w3
{ V:0uy>
= h<? /Krs
Rktn/Vi
} xu_XX#9?b
:YRzI(4J
//线程睡眠 JucxhjV#,
public static void sleep(int nSecond) {P<BJ52=
{ [FAOp@7W
try{ 7fN&Q~.
Thread.sleep(nSecond); jnU*l\,
} XTi0,e]5{u
catch(Exception e) Sf4h!ly
{ }VGI Y>v
e.printStackTrace (); P/gb+V=g!
} iRj x];:Vu
} 0oi5]f6g?8
LO$#DHPt
//日志 xo)?XFM2
public static void log(String sMsg) YCB 3
{ jB/q1vFO
System.err.println(sMsg); bKt3x+x(
} O%++0k;
u>Axq3F
A^r [_dyZ
public static void log(int sMsg) XvzV lKL
{ sAj$U^Gp
System.err.println(sMsg); a[#BlH
} ~_6rD`2cJ
} $(hZw
\EqO;A%<
'7%9Sqx
/* of<OOh%3
**TestMethod.java 8;bOw
*/ a#@opUn-
package NetFox; RR9s%>^
;0WlvKF
<Z wEdq
public class TestMethod { #7)6X:/O
zoXF"Nz
aUQq<H'R
public TestMethod() #]a0 51Y
{ ///xx/weblogic60b2_win.exe Z r*ytbt
try{ YI/vt2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >8c9-dTmf
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *e=e7KC6kI
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6N^FJCs
fileFetch.start(); v "07H
} NB[b[1 Ch
catch(Exception e){e.printStackTrace ();} U-(d~]$
d+kIof,
7_LE2jpC,5
} %~@}wHMB
oVs&r?\Z
V@F~Cx
public static void main(String[] args) <D?`*#K
{ q;U[f6JjE
new TestMethod(); ?6|EAKJ`lK
} 16AYB17
} 3>Yec6Hs
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