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)); UEkn@^&bg
} K ?R* )_
for(int i=0;i<nEndPos.length-1;i++) !h\>[O
{ 6k569c{7
nEndPos = nStartPos[i+1]; ([vyY}43h
} 9 GEMmo3
nEndPos[nEndPos.length-1] = nFileLength; @D$^- S6
} Tvdg:[V<
} ."HDUo2D7
hn-+]Y:
^ud-N;]MKs
//启动子线程 LmCr[9/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =EE>QM
for(int i=0;i<nStartPos.length;i++) R<* c
{ k9]M=eO
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H]i.\2z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bA/,{R
nStartPos,nEndPos,i); /=o~7y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Pn&!C*,
fileSplitterFetch.start(); G)<NzZo
} x?5D>M/Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {Y0Uln5u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1#]0\Y(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4gyC?#Ede
nEndPos = " + nFileLength); _SVIY@K|/
// fileSplitterFetch[nPos.length-1].start(); O$ p
\W%Aeg*c
cOhx
//等待子线程结束 ,q[aV 6kO
//int count = 0; \&[Jtv *
//是否结束while循环 d'bAM{R>
boolean breakWhile = false; 0O@UT1M;v
idG}p+(;
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while(!bStop) cD&QN9
{ B4uJT~,7>
write_nPos(); NFYo@kX> G
Utility.sleep(500); Ev%_8CO4e
breakWhile = true; k4@$vxy0
H YA<
_BC%98:WP
for(int i=0;i<nStartPos.length;i++) ,}8|[)"
{ )\xDo<@
if(!fileSplitterFetch.bDownOver) Hj\iI p
{ gAFu
breakWhile = false; [.ya&E)x
break; \my5E\
} moop.}O<
} jUtFDw
if(breakWhile) VXfp=JE
break; sN"JVJXi
Ah_,5Z@&R
9i^dQV.U=
//count++; +1uAzm4SL
//if(count>4) \E}YtN#
// siteStop(); 2cnyq$4k
} j'\!p):H
[wLK*9@&
S)n+E\c
System.err.println("文件下载结束！"); d9qA\ [
} a;GuFnfn,
catch(Exception e){e.printStackTrace ();} s|cL mL[
} k'(d$;Jgr
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v@qU<\Y>
//获得文件长度 ;$il_xA)\>
public long getFileSize() :"ta#g'
{ 47/14rY 2
int nFileLength = -1; ?QbxC,& i
try{ 0Z11V9Jk
URL url = new URL(siteInfoBean.getSSiteURL()); @N(*1,s2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NQ9/,M
httpConnection.setRequestProperty("User-Agent","NetFox"); [9-&Lq_ g
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],?$&
int responseCode=httpConnection.getResponseCode(); 3RbPc8($Y
if(responseCode>=400) [?QU'[
{ jV)4+D
processErrorCode(responseCode); REK(^1 h
return -2; //-2 represent access is error 5LYzX+a)
} Hv3<gyD
;ZasK0
y;$ !J
String sHeader; @,9cpaL3
)iU@P7W=
m-wK8]t9
for(int i=1;;i++) 9 SBVp6'
{ Rr%CP[bH
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [$x&J6jF.
//Utility.log(in.readLine()); ^!FLi7X
sHeader=httpConnection.getHeaderFieldKey(i); .XZq6iF9
if(sHeader!=null) X5Fi , /H
{ 5`3Wua
if(sHeader.equals("Content-Length")) uOv0ut\\G
{ :(?F(Q^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l,lfkm
break; CRh.1-
} ?as1^~
} IEP^u `}
else )%(V.?eW
break; Q7{/ T0
} 7_G$&
} mne?r3d
catch(IOException e){e.printStackTrace ();} #X`qkW.T<
catch(Exception e){e.printStackTrace ();} C1M @;
.7`c(9<
S^zt>
Utility.log(nFileLength); BYKONZu
XwlF[3VbiX
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return nFileLength; Y0?<~Gf
} U;qGUqI
]Jum(1Bo
>"/Sa_w
//保存下载信息（文件指针位置） DKG99biJN
private void write_nPos() b"PRa|]
{ 7`pK=E}+
try{ OMz_xm.UPi
output = new DataOutputStream(new FileOutputStream(tmpFile)); QIWfGVc-
output.writeInt(nStartPos.length); EyK F5TP0
for(int i=0;i<nStartPos.length;i++) U=vh_NHj
{ G@=H=' :~
// output.writeLong(nPos); NGs@z^&V
output.writeLong(fileSplitterFetch.nStartPos); OH_mZA
output.writeLong(fileSplitterFetch.nEndPos); 7lH.>n
} u|Tg*B
output.close(); ZR*Dl.GWY
} j96\({;k
catch(IOException e){e.printStackTrace ();} ,?KN;~t#vz
catch(Exception e){e.printStackTrace ();} +>BD^[^^
} 6qF9+r&e?
'<!T'l:R:/
<?E~Qc t
//读取保存的下载信息（文件指针位置） Oe_*(q&
private void read_nPos() `%<^$Ng;
{ ~6!TMVr
try{ _Z0O]>KH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #[ TOe
int nCount = input.readInt(); ]7/6u.G7R
nStartPos = new long[nCount]; 8w\ZY>d
nEndPos = new long[nCount]; *f*o ,~8V1
for(int i=0;i<nStartPos.length;i++) WW[Gne
{ )d =8)9B
nStartPos = input.readLong(); $8;`6o`
nEndPos = input.readLong(); D"vl$BX
} <ZXK}5SZ#
input.close(); t \;,$i
} {~0r3N4Zl
catch(IOException e){e.printStackTrace ();} ":Uv u[-
catch(Exception e){e.printStackTrace ();} .?NraydwV
} D6NgdE7b
F&6Xo]?
bL9XQ:$C
private void processErrorCode(int nErrorCode) ,+U,(P5>s
{ 2)4oe
System.err.println("Error Code : " + nErrorCode); ELgq#z
} ~^ ^|]s3
CS\T@)@t
^,sKj-
//停止文件下载 T~G~M/
public void siteStop() tEl_a~s*3?
{ a`E1rK'
bStop = true; &Z%|H>+;T
for(int i=0;i<nStartPos.length;i++) tjWf`#tH>H
fileSplitterFetch.splitterStop(); oRZ--1oR_
4cQ|"sOzD
upefjwm
} Bf+7;4-
} svj0;x5
//负责部分文件的抓取 Ns#R`WG)
**FileSplitterFetch.java UWIw/(Mv/]
*/ sF!nSr
package NetFox; 7]pi.1i
7>$&CWI
f~-Ipq;F
import java.io.*; *L+)R*|:&
import java.net.*; $PbwC6>8
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public class FileSplitterFetch extends Thread { mZ!1Vh
#57D10j
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String sURL; //File URL o^*k
long nStartPos; //File Snippet Start Position qrt2BT)
long nEndPos; //File Snippet End Position $`'Xb
int nThreadID; //Thread's ID RA^-Pa.O
boolean bDownOver = false; //Downing is over rhQv,F9
boolean bStop = false; //Stop identical HTw7l]]
FileAccessI fileAccessI = null; //File Access interface {~a+dEz
4O1[D?)`x
%D $+Z(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %[J|n~8_Z
{ ?o883!&v
this.sURL = sURL; vC|V8ea
this.nStartPos = nStart; xa]e9u%
this.nEndPos = nEnd; ['#3GJz-
nThreadID = id; )a0%62
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;($"_h
} /^^wHW:
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JR^#NefJ
public void run() yf@DaIG
{ Unc_e
while(nStartPos < nEndPos && !bStop) )D>= \Me
{ *wNO3tP't
5 4vDP9
x-Ug(/!^
try{ Kjfpq!NYE
URL url = new URL(sURL); *fg|HH+i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BELxaV,
httpConnection.setRequestProperty("User-Agent","NetFox"); SM1[)jZ-
String sProperty = "bytes="+nStartPos+"-"; y~-dQ7r
httpConnection.setRequestProperty("RANGE",sProperty); Yj#4{2A
Utility.log(sProperty); |a{~Imz{
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#dEMjD
InputStream input = httpConnection.getInputStream(); &* 1iW(x
//logResponseHead(httpConnection); oJ`cefcWo
'pQ\BH
8AQ@?\Rc"2
byte[] b = new byte[1024]; vAH`tPi>
int nRead; {(j1#9+9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =*Ru2
{ FdFN4{<QZ
nStartPos += fileAccessI.write(b,0,nRead); |xX>AMZc)D
//if(nThreadID == 1) Jh!'"7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pon0!\ZT=
} XJ{b_h#N
+#=l{_Z,ZJ
$Q'S8TU
Utility.log("Thread " + nThreadID + " is over!"); p|,3X*-ynx
bDownOver = true; nQ}$jOU&
//nPos = fileAccessI.write (b,0,nRead); rUOl+p_47
} *CS2ndp
catch(Exception e){e.printStackTrace ();} Y}UVC|Ef
} M,(UCyT
} V<W$h`
nr>Os@\BU
V3t;V-Lkt
//打印回应的头信息 nLcOz3h
public void logResponseHead(HttpURLConnection con) K%iA-h
{ KVA~|j B
for(int i=1;;i++) AttS?TZr
{ O=2SDuBZ
String header=con.getHeaderFieldKey(i); j8|N;;MN
if(header!=null) {IR-g,B
//responseHeaders.put(header,httpConnection.getHeaderField(header)); E3P2
Utility.log(header+" : "+con.getHeaderField(header)); g+ P
else 8 O% ?t
break; w4%yCp[,
} y)]L>o~
} 1Bhd-
q[Ed6FM$~
c3]X#Qa#m$
public void splitterStop() 7ElU5I<S
{ 2ms@CQy(00
bStop = true; zc#$hIi
} b<1+q{0r
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%UnL,V9)
} )ZqY`by!
gtVnn]Jh
&8R!`uh1
/* :,[=g$CT:
**FileAccess.java d]!`II
*//文件访问(定位，写) 5?M d
package NetFox; ^p}|""\j
import java.io.*; SoPiEq
N:nhS3N<L
"2 "gTS
public class FileAccessI implements Serializable{ ;(I')[R"
,UE>@;]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m&!4*D
RandomAccessFile oSavedFile; h qT6]*
long nPos; ).D+/D/"2
Rt=zqfJ
Q-7C'|
public FileAccessI() throws IOException LUN"p#1
{ -Mx\W|YK
this("",0); wu53e= /
} YOE!+MiO
4_&+]S
k?7V#QW(
public FileAccessI(String sName,long nPos) throws IOException o{r<=X ysM
{ RW I7eC
oSavedFile = new RandomAccessFile(sName,"rw"); #ssSs]zl
this.nPos = nPos; jS<(Oo
oSavedFile.seek(nPos); %f'mW2
} E=eK(t(8
noL&>G
pN?geF~t|
public synchronized int write(byte[] b,int nStart,int nLen) }XcYIo#+t
{ T_3JAH e
int n = -1; XMpa87\
try{ {a6cA=WTPd
oSavedFile.write(b,nStart,nLen); '"Z\8;5i
n = nLen; t'{IE!_
} "`q:
catch(IOException e) g+1&liV
{ ~>-MVp
e.printStackTrace (); p;0p!~F=49
} Y5,[udF:O
":!7R<t
NcMohpkq
return n; ^T&@(|o
} AAW])c`.
/|MHZ$Y9w?
LfsqtQ=J`
} mtd ,m
pEp`Z,p
7G]v(ay
/* vnr{Ekg
**SiteInfoBean.java 9Q/t+
*/ x,81#=m^h
package NetFox; ::`#qa4!
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734f&2
public class SiteInfoBean { 0s'h2={iI
}"x#uG
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private String sSiteURL; //Site's URL k3yA*Ec
private String sFilePath; //Saved File's Path $s.:H4:I
private String sFileName; //Saved File's Name (<KFA,
private int nSplitter; //Count of Splited Downloading File hteAuz4H
4}xw&x
2&o jQhe
public SiteInfoBean() I6-.;)McO
{//nSplitter的缺省值为5 v1O1-aM
//default value of nSplitter is 5 >K;DBy*
this("","","",5); =IH~:D\&
} o|G[/o2
XDQ5qfE|
c$P68$FB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) JEh(A=Eu>
{ kVe4#LT
sSiteURL= sURL; YMr2|VEU[
sFilePath = sPath; ,7h0y
sFileName = sName; "zZZ h
this.nSplitter = nSpiltter; `~k`m{4.a
6Q*Zy[=
*YO^+]nmY
} N5d)&a 7?
gzd<D}2F~
Kg6[
public String getSSiteURL() e%_J O7
{ OaeX:r+&Q
return sSiteURL; vN9R.R
} cMK}BHOC
E^4}l2m_
ORx6r=zg
public void setSSiteURL(String value) c4V%>A
{ iz%wozf
sSiteURL = value; cXod43
} \)`OEGdOR\
ko{7^]gR
U[EZ,7n8
public String getSFilePath() ^V7'S<
{ c:I %jm
return sFilePath; 1Eh6ti
} Y?v{V>;*A
G_]zymXQ
U!i1~)s
public void setSFilePath(String value) ]_(J8v
{ uL{CUt
sFilePath = value; /*2)|2w
} IqAML|C
|i\%>Y,
+l hJ8&
public String getSFileName() lG5KZ[/Or
{ '\M]$`Et
return sFileName; 5=_bK^Am
} Tx>V$+al
fSF_O}kLp
gY&WH9sp?9
public void setSFileName(String value) s[bQO1g;*
{ \IaUsx"#o{
sFileName = value; ZM16 ~k
} $1 t IC_
WZM
UR~s\m
public int getNSplitter() $f?GD<}?7r
{ v>0I=ut
return nSplitter; p""\uG'
} +"1fr
.XT]\'vW
-v! ;
public void setNSplitter(int nCount) gA}?X
{ zfw=U \
nSplitter = nCount; qV0GpVJZU?
} wxo*\WLe
} G=/^]E
#y-R*4G
Du #>y!
/* Cto>~pV
**Utility.java c] -
*/ +ib&6IU
package NetFox; (q@%eor&}
hg2Ywzfm-
2]]}Xvx4#
public class Utility { h~lps?.#b
ot0g@q[3
5PsjGvm.%
public Utility() n^|SN9_r
{ l >~Rzw
=o4gW`\z
\%&):OD1
} D"gv:RojD
d uP0US
//线程睡眠 8*;>:g
public static void sleep(int nSecond) sJ{r+wY
{ 8<Pi}RH
try{ ~b@"ir+g4
Thread.sleep(nSecond); Z((e-T#,
} 5"y)<VLJX
catch(Exception e) G.r .Z0
{ gO{$p q}
e.printStackTrace (); cJf&R^[T
} )t((x
} 85e*um^
_6!iv
//日志 lid0 YK-
public static void log(String sMsg) !mmSF1f
{ Tm$8\c4V:*
System.err.println(sMsg); }@"v7X $
} v"o_V|
`=S%!akj
x2TE[#><
public static void log(int sMsg) |8tKN"QG
{ Po&'#TC1
System.err.println(sMsg); # [ +n(
} #&ei
} +IMt$}7[
,`PYU[
ht#,v5oG>f
/* EeHghq
**TestMethod.java @Ko#nDEq
*/ -/ G#ls|?
package NetFox; 39MOqVc
5g.w"0MkY
qHgzgS7a
public class TestMethod { U&43/;<,
!L( )3=
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public TestMethod() kZhd^H.
{ ///xx/weblogic60b2_win.exe IwBO#HR~)
try{ D<:zw/IRE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K:A:3~I!NW
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v}id/brl
SiteFileFetch fileFetch = new SiteFileFetch(bean); *2fJdY
fileFetch.start(); );h
} XD" 4t4~>
catch(Exception e){e.printStackTrace ();} @+1AYVz(k
B`gH({U
I2krxLPd
} 0dQ\Y]b
Z?d][zGw
q&}+O
public static void main(String[] args) i9V,
{ c$lZ\r"
new TestMethod(); mN>(n+ly
} Q+/P>5O/
} x0%yz+i{:
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