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)); F~fBr
} T9&{s-3*
for(int i=0;i<nEndPos.length-1;i++) }T(=tfv@
{ ~!~i_L\V
nEndPos = nStartPos[i+1]; u&uFXOc'
} `ovMfL.u
nEndPos[nEndPos.length-1] = nFileLength; KJ32L
} Q"D
} j0~am,yZ
jT$J~MpHh
6xtgnl#T
//启动子线程 uA[ :
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; aVK,(j9u
for(int i=0;i<nStartPos.length;i++) & [@)Er=
{ 4-SU\_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IB|6\uKn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &U?4e'N)T
nStartPos,nEndPos,i); U)Hc7% e
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HVoPJ!K3
fileSplitterFetch.start(); 4)D~S4{E5
} "5<!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ><D2of|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B>:U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", i6k6l%
nEndPos = " + nFileLength); 0C%IdV%CU
// fileSplitterFetch[nPos.length-1].start(); lSaX!${R'T
XXn3K BIf
N,rd= m+
//等待子线程结束 ] &"`
//int count = 0; qQ^CSn98J
//是否结束while循环 7r'_p$
boolean breakWhile = false; Ul/m]b6-
/huh}&NNu
FCEmg0qdjD
while(!bStop) "Y L^j~A
{ t?-a JU
write_nPos(); r'#!w3*Cy
Utility.sleep(500); O.X;w<F/V
breakWhile = true; ;@ixrj0u
rZpsC}C'
],0I`!\
for(int i=0;i<nStartPos.length;i++) dR.?Kv(,E
{ LKcp.i
if(!fileSplitterFetch.bDownOver) BWxJ1ENM
{ qx1Js3%
breakWhile = false; EGqu-WBS
break; .6$=]hdAp
} }"WovU{*s
} !Whx^B:
if(breakWhile) AQ(n?1LU
break; B*O/>=_
?+7~E8
TO5y.M|7
//count++; n:wAxU
//if(count>4) @OT$* Qh
// siteStop(); fi>.X99(G
} :3R3>o6m
zLe(#8G
E_A5KLP
System.err.println("文件下载结束！"); AEnkx!o
} KG(FA
catch(Exception e){e.printStackTrace ();} VT4>6u}
} 0_ST2I"Ln
\.iejB
qS! Lt3+
//获得文件长度 ~=c5q
public long getFileSize() bws}'#-*
{ zE1=P/N
int nFileLength = -1; QnBWZUI
try{ G)[gLD{g?
URL url = new URL(siteInfoBean.getSSiteURL()); 3=oxT6"k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cSB_b.@"1
httpConnection.setRequestProperty("User-Agent","NetFox"); +{=U!}3|
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w<THPFFF"
int responseCode=httpConnection.getResponseCode(); Nb3O>&J
if(responseCode>=400) G$'UK
{ eP:\\; ;
processErrorCode(responseCode); 6p&2A
return -2; //-2 represent access is error }z/%b<o_
} %7`eT^
U_'M9g{,<
}jC^&%|
String sHeader; MtPdpm6\
2^`k6V!
vs+aUT C\
for(int i=1;;i++) 9pj6`5Zn@6
{ u@:[ dbJ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K@2"n| S;
//Utility.log(in.readLine()); $Lbamg->E
sHeader=httpConnection.getHeaderFieldKey(i); zmD7]?|
if(sHeader!=null) t+F_/_"B
{ N.Q}.(N0
if(sHeader.equals("Content-Length")) seAPVzWUU
{ #+_=(J
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iuXXFuh
break; T zS?WYF
} ,d lq2
} i9qIaG/
else PWp=}f.y
break; 8EJP~bt
} HbPn<x^7
} V>obMr^5
catch(IOException e){e.printStackTrace ();} ?-2s}IJO
catch(Exception e){e.printStackTrace ();} B>cT<B
Nc[N 11?O
Zw{?^6;cS
Utility.log(nFileLength); GNuIcy
j-"34
TUwX4X6m
return nFileLength; N8kNi4$mp=
} =a+ } 6
2/A*\
H{i|?a)
//保存下载信息（文件指针位置） NhTJB7
private void write_nPos() n,s7!z/
{ 4,R"(ej
try{ b?,%M^9\`
output = new DataOutputStream(new FileOutputStream(tmpFile)); "WtYqXyd
output.writeInt(nStartPos.length); j$s/YI:
for(int i=0;i<nStartPos.length;i++) 4bw4!z9G
{ 9Qu(RbDqC
// output.writeLong(nPos); m:0[as=
output.writeLong(fileSplitterFetch.nStartPos); hP.Km%C)0n
output.writeLong(fileSplitterFetch.nEndPos); g2==`f!i
} KTot40osj
output.close(); YuIF}mUr"
} O/#uQn}
catch(IOException e){e.printStackTrace ();} +03/A`PKrB
catch(Exception e){e.printStackTrace ();} 6;s[dw5T
} 2)0J@r'
1k)pJzsc
bd}[X'4d
//读取保存的下载信息（文件指针位置） 0,@^<G8?
private void read_nPos() Svo\+S
{ 6yAZvX
try{ nnT#S
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [.Fq l+
int nCount = input.readInt(); -nHkO&&R
nStartPos = new long[nCount]; 1\aTA,
nEndPos = new long[nCount]; (@!K tW
for(int i=0;i<nStartPos.length;i++) :06.b:_
{ 7mXXMm
nStartPos = input.readLong(); #XqCz>Z
nEndPos = input.readLong(); L$);50E
} |`o1B;lc
input.close(); w8UUeF
} =)g}$r &<
catch(IOException e){e.printStackTrace ();} @b.,pwZF
catch(Exception e){e.printStackTrace ();} 4]p#9`j
} ,:'JJZg@
?ILjt?X8
&!WRa@x0I
private void processErrorCode(int nErrorCode) [dFcxzM-N
{ $%31Gk[I
System.err.println("Error Code : " + nErrorCode); |=,jom
} HYT~AO-!
I 2OQ
IDos4nM27]
//停止文件下载 4<E <sD
public void siteStop() -Hw3rv3o
{ BgdUG:;&
bStop = true; } d8\ Jg
for(int i=0;i<nStartPos.length;i++) LA2/<:
fileSplitterFetch.splitterStop(); &hL2xx=
]e"!ZR?XJ
,!%E\`
} cqs.[0 z#B
} #Y
//负责部分文件的抓取 Lr8|S
**FileSplitterFetch.java 'yA/sZ
*/ V'Kied+
package NetFox; ~$[fG}C.K
]W2#8:i
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import java.io.*; >D~8iuy]8.
import java.net.*; 4~FRE)8
Qyx~={.C~
nIfAG^?|*
public class FileSplitterFetch extends Thread { <BZC5b6
oCI\yp@a
,5}w]6bCr
String sURL; //File URL |Z2"pV
long nStartPos; //File Snippet Start Position q%$p56\?3
long nEndPos; //File Snippet End Position E7@Gpu,o
int nThreadID; //Thread's ID ~UO}PI`C
boolean bDownOver = false; //Downing is over :@-yK8q's
boolean bStop = false; //Stop identical !P^Mo> "
FileAccessI fileAccessI = null; //File Access interface uG6.(A1LM
<1>6!`b4
Z~-N'Lt{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W
{ UXpp1/d|e
this.sURL = sURL; g%[:wjV;
this.nStartPos = nStart; wik<#ke
this.nEndPos = nEnd; C|3Xz[k{
nThreadID = id; g<0K i^#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 J!5b~8`v
} .7b%7dQ<\
=4SXntU!e
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public void run() =*lBJ-L
{ CyYr5 Dz
while(nStartPos < nEndPos && !bStop) $HQ4o\~
{ .RFH@''
rQ]JM
6<fG;:
try{ =G^'wwpv(
URL url = new URL(sURL); =QtFJ9\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7[qL~BT+
httpConnection.setRequestProperty("User-Agent","NetFox"); N5sVRL"7
String sProperty = "bytes="+nStartPos+"-"; GxG~J4
httpConnection.setRequestProperty("RANGE",sProperty); Tjrb.+cua
Utility.log(sProperty); L2EQ 9i'[
C5TV}Bq\
'&Y_,-i
InputStream input = httpConnection.getInputStream(); c$&({Z{1
//logResponseHead(httpConnection); YOGj__:
0\ (:y^X
Gvh"3|u?z
byte[] b = new byte[1024]; /PTRe5-7
int nRead; {dpDQP +!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <Ohi+a%6
{ Z10}xqi!X
nStartPos += fileAccessI.write(b,0,nRead); ! {G0'
//if(nThreadID == 1) >|kD(}Axf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zN[& iKf
} ,z/aT6M?H
E/%"%&`8j
YT(Eh3ID
Utility.log("Thread " + nThreadID + " is over!"); C]5 kQ1Og
bDownOver = true; kV?fie<\)
//nPos = fileAccessI.write (b,0,nRead); Bz-jy.
} ^w~B]*A:"
catch(Exception e){e.printStackTrace ();} H~Vf;k>
} 6V JudNA
} $'Mf$h
;2&"
LAxN?ok9gD
//打印回应的头信息 6Nn+7z<*&z
public void logResponseHead(HttpURLConnection con) GVnDN~[
{ 8/dMvAB1So
for(int i=1;;i++) Qm[s"pM
{ hd9HM5{p
String header=con.getHeaderFieldKey(i); ztSQrDbbb4
if(header!=null) (M$>*O3SR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c6 mS
Utility.log(header+" : "+con.getHeaderField(header)); -X$EE$:
else wxh\CBxG
break; QtKcv7:4
} UiH7
} @g5y_G{SP
]&Y^
5{V"!M+<
public void splitterStop() ;j1E6
{ <Jhd%O
bStop = true; ]Rxo}A
} QWfSm^ t
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} ;n(f?RO3X
%hYgG;22
l|gi2~ %Y
/* Vl5>o$G|<.
**FileAccess.java g_syGQ\
*//文件访问(定位，写) /ie&uWy
package NetFox; %w65)BFQ
import java.io.*; L>sLb(2\i
~KS@Ulrox
Zhfg
public class FileAccessI implements Serializable{ fIQ,}>
66eJp-5e8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K}@rte
RandomAccessFile oSavedFile; r]p3DQ
long nPos; 8N'hG,
QNMZR
|@JTSz*Or
public FileAccessI() throws IOException BkXv4|UE
{ 4DCh+|r
this("",0); `~u=[}w
} OmWEa
Yt(FSb31H
E! NtD).=S
public FileAccessI(String sName,long nPos) throws IOException mv8H:T
{ Gr2}N"X=
oSavedFile = new RandomAccessFile(sName,"rw"); %BkE %ZcZ
this.nPos = nPos; uKk#V6t#
oSavedFile.seek(nPos); 'D5J5+.z
} a`w=0]1&*
>EJ{ *
iLSUz j`
public synchronized int write(byte[] b,int nStart,int nLen) K.}jOm
{ 3/n?g7B
int n = -1; V[/9?5pM
try{ :;eOhZ=_
oSavedFile.write(b,nStart,nLen); iptA#<Yj
n = nLen; :P_h_Tizv
} 8+oc4~!A@n
catch(IOException e) 7w)8s
{ Ljz)%y[s
e.printStackTrace (); 2T2<I/")O
} G^)]FwTs
a^J(TW/
]C,j80+pK
return n; }VJ>}i*
} ,g7O
Sr6'$8#>Y
^;PjO|mD Z
} Q;3`T7
?`?Tg&W
j.Uy>ol
/* #1J,!seJ
**SiteInfoBean.java IwnDG;+Ap
*/ RG45S0Ygj
package NetFox; lF(v<drkB
}XBF#BN
cF15Mm2
public class SiteInfoBean { I*a@_EO
#(614-r/
p+=zl`\=|
private String sSiteURL; //Site's URL k(H]ILL
private String sFilePath; //Saved File's Path md{nHX&
private String sFileName; //Saved File's Name K@1gK<,a
private int nSplitter; //Count of Splited Downloading File S&UP;oc
_oc6=Z
bDWLHdu a
public SiteInfoBean() zS;ruK%2
{//nSplitter的缺省值为5 m=9b/Nr4
//default value of nSplitter is 5 A` _dj}UF
this("","","",5); q#AEu xI1
} p)B/(%
QO;Dyef7b
PzKTEYJL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u|IS7>Sm
{ `"CA$Se8
sSiteURL= sURL; GZaB z#U
sFilePath = sPath; xbCR4upS
sFileName = sName; ||X3g"2W9
this.nSplitter = nSpiltter; ~2rQ80_
>|%3j,<U
kNWTM%u9
} e+BZoK ^
Rf4K Rhi
m@kLZimD
public String getSSiteURL() "W+>?u)
{ `$jun
return sSiteURL; vE(]!CB
} 7#j.yf4
7 w,D2T
k ?KJ8
public void setSSiteURL(String value) ( xooU 8d
{ X9?)P5h=
sSiteURL = value; MUl7o@{'
} %7mGMa/
nQV0I"f]?]
Vc5>I_
public String getSFilePath() W6>t!1oO+
{ [r"Oi| 8I
return sFilePath; T=YVG@fm?
} fmK~?
8:c=h/fa
F&!vtlV)
public void setSFilePath(String value) ]CLM'$
{ toGd;2rl
sFilePath = value; ?0:]%t18
} tx d0S!
Z#@
`oNJ=,p
public String getSFileName() 2LN6pu
{ X7-*`NI^
return sFileName; sDNWB_~
} \;MP|:{pU
[ S
}.045 Wuu
public void setSFileName(String value) bj@sci(1?
{ ,&@GxiU
sFileName = value; g5Hsz,x
} r Z5eXew6
d9 8pv%
EjVB\6,
public int getNSplitter() y;9K
{ NVC$8imip
return nSplitter; )[sSCt]
} q|D*H9[ke
;NJM3g0I
H~hAm
public void setNSplitter(int nCount) 1nLFtiki
{ f'Xz4;
nSplitter = nCount; ^n]?!BdU
} 78b9Sdi&
} =(k0^#++G
hU2N{Ac
tK <)A)
/* ER$~kFE2yP
**Utility.java kS7T'[d
*/ Y50$2%kM
package NetFox; ~0.@1zEXj
YX2j;Y?
]}0+7Q
public class Utility { / dn]`Ge)
R91u6r#
D3 E!jQ1
public Utility() 2gjA>ET`N
{ 483vFLnF
QaEXk5>e
KQqQ@D&n
} JeCEj=_Z
M9S[{Jj*
//线程睡眠 `V0]t_*D
public static void sleep(int nSecond) 7 ~ Bo*UM
{ wY}+d0Ch
try{ ~RE`@/wQ]
Thread.sleep(nSecond); Y.Ew;\6U
} 8%U)EU
catch(Exception e) t,P+~ A
{ 54LCoG/
e.printStackTrace (); 9zd)[4%=
} (C QgT3V
} {k~$\J?.
a. 5`Q2
//日志 ~JT{!wcE}o
public static void log(String sMsg) eS Fmx
{ [K9q+
System.err.println(sMsg); 9k"nx ,"
} #wm)e)2@
bmddh2
]X _&
public static void log(int sMsg) j({L6</x
{ RMrt4:-DI
System.err.println(sMsg); gA) F
} uTJ?@^nq
} Cw^)}23R
EGMcU|yL
>"nk}@
/* #QDV_ziE5
**TestMethod.java I2l'y8)d
*/ a+BA~|u^
package NetFox; Em.?
W]*wxzf!5z
& ='uAw
public class TestMethod { K|1^?#n
<?nr"V
Vis?cuU/
public TestMethod() E0h!%/+-L
{ ///xx/weblogic60b2_win.exe kI;^V
try{ WK^qYfq|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Tp6ysjao
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nMbV{h ,
SiteFileFetch fileFetch = new SiteFileFetch(bean); #5I "M WA
fileFetch.start(); t[ MRyi)LF
} ?^+|V,<
catch(Exception e){e.printStackTrace ();} q B2#EsZ
1Q$ M/}
xX>448=
} U)o8Tr
?8nG F%p
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public static void main(String[] args) Ek.j@79
{ RGKJO_*J2
new TestMethod(); QBo^{],
} tr}$82Po
} wLbnsqa
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