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)); ~uWOdm-"[
} &[vw 0N-
for(int i=0;i<nEndPos.length-1;i++) (2ot5x}`j
{ Sjj>#}U
nEndPos = nStartPos[i+1]; =8Jfgq9E
} M~e0lg8
nEndPos[nEndPos.length-1] = nFileLength; :M3oUE{
} thlY0XCq,%
} ;|T!#@j
N"tFP9;K
BR`ygrfe
//启动子线程 OR1DYHHT/1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; y&~w2{a
for(int i=0;i<nStartPos.length;i++) Vv.r8IGYm
{ :ue:QSt(u
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *|.0Myjo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gmKGy@]
nStartPos,nEndPos,i); =WbOwI)u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Bq\F?zk<
fileSplitterFetch.start(); p9!"O
} /1=4"|q>h'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Rd \.:u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); c,MOv7{x_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s9;#!7ms
nEndPos = " + nFileLength); 'NjzgZ~]P
// fileSplitterFetch[nPos.length-1].start(); 7,qYV}
E51dV:l
}_/Hdmmx
//等待子线程结束 O|IG_RL]
//int count = 0; BF*kb2"GZ6
//是否结束while循环 $ i)bq6
boolean breakWhile = false; @}p2aV59
H(c72]@Vg
lf{e[!ML'
while(!bStop) ~)LH='|h\}
{ E907fX[R~
write_nPos(); Ix@&$!'k
Utility.sleep(500); e1(Q(3
breakWhile = true; /-_=nf}w
x5`br.b
|:[tNs*,O
for(int i=0;i<nStartPos.length;i++) +CH},@j
{ K;?,FlH
if(!fileSplitterFetch.bDownOver) <~ad:[
{ 6fH@wQ"wN
breakWhile = false; q\Q{sv_
break; (/!r(#K0,'
} #4MBoN(3
} <9E0iz+j
if(breakWhile) ptatzp]c#
break; 5Wyz=+?m|
qf@q]wtar
LZJA4?C
//count++; Ee)[\Qjn
//if(count>4) Ds#/
// siteStop(); kIw`P[
} E#J';tUQ
Wt)Drv{@ {
'w>_+jLT
System.err.println("文件下载结束！"); #/"8F O%~p
} mpAR7AG6
catch(Exception e){e.printStackTrace ();} W>r#RXmh
} >EL)X #e
hT$~ygQ
qPB8O1fyU
//获得文件长度 H9h@sSg
public long getFileSize() IEKU-k7}Z
{ #_lt~^6
int nFileLength = -1; C{sLz9
try{ U~h'*nV&
URL url = new URL(siteInfoBean.getSSiteURL()); xq-17HKs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7^wc)E^H
httpConnection.setRequestProperty("User-Agent","NetFox"); :tIC~GG]_)
IDkWGh
*n]7
int responseCode=httpConnection.getResponseCode(); 2LrJ>Mi
if(responseCode>=400) ~$'\L
{ \!(
processErrorCode(responseCode); 'O5'i\uz
return -2; //-2 represent access is error RZM"~ 0
} D3|oOOoG
QM3,'?ekRH
0TfS=scT
String sHeader; tz#gClo
4h@Z/G!T3
/9o!*K
for(int i=1;;i++) JnHo9K2.
{ !d<"nx[2`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k(zsm"<q
//Utility.log(in.readLine()); V.os
sHeader=httpConnection.getHeaderFieldKey(i); O: @}lK+H
if(sHeader!=null) NCxqh<
{ RoCfJ65
if(sHeader.equals("Content-Length")) hN['7:bQ
{ V"p!Bf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M?=;JJ:
break; da1]mb=4 5
} GN KF&M
} OB[o2G<0
else 'n<iU st
break; SyAvKd`g
} /C/id)h>
} )p!7#v/@f
catch(IOException e){e.printStackTrace ();} jiF?fX@
catch(Exception e){e.printStackTrace ();} U4 13?Pe
D:Q 21Ch
IbcZ@'RSw
Utility.log(nFileLength); >^Se'SE]
-n'F v@U
)c l5B{1P
return nFileLength; aM7uBx\8 5
} >A0k 8T
RI68%ZoL
sXd8rj:o
//保存下载信息（文件指针位置） rr#K"SP
private void write_nPos() ;raN
{ B||;'
try{ -P&6L\V
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9f\/\L
output.writeInt(nStartPos.length); W8lx~:v
for(int i=0;i<nStartPos.length;i++) 5,)Qw
{ p7:{^
// output.writeLong(nPos); AfG/JWSo}
output.writeLong(fileSplitterFetch.nStartPos); WK="J6K5
output.writeLong(fileSplitterFetch.nEndPos); w.&1%X(k
} '#(v=|J
output.close(); )K'N(w
} aZEn6*0B
catch(IOException e){e.printStackTrace ();} <C9 XX~
catch(Exception e){e.printStackTrace ();} [F5h
} ""s]zNF}
0rGSH*(
' B
//读取保存的下载信息（文件指针位置） ICAH G7,
private void read_nPos() Me6+~"am/
{ .S(,o.
try{ ~+Z{Q25R
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :VF<9@t
int nCount = input.readInt(); lg047K
nStartPos = new long[nCount]; OgF+OS
nEndPos = new long[nCount]; jE#O>3+.
for(int i=0;i<nStartPos.length;i++) gKOOHUCb
{ ,;M4jc{
nStartPos = input.readLong(); !"+'A)Nve
nEndPos = input.readLong(); iS5W>1]
} O5H9Y}i]
input.close(); hDV20&hq
} F@R1:M9*
catch(IOException e){e.printStackTrace ();} 3s"0SLS4
catch(Exception e){e.printStackTrace ();} PvGDTYcKp
} 31EyDU,W
RZ1 /#;
Fu^^i&
private void processErrorCode(int nErrorCode) &K/FyY5
{ \^#~@9
System.err.println("Error Code : " + nErrorCode); W+*5"h
} *m2=/Sh
gIA@l`"
sBV4)xM
//停止文件下载 1Z{ZV.!
public void siteStop() O$IjNx
{ m^x6>9,
bStop = true; D~o$GW%
for(int i=0;i<nStartPos.length;i++) N41R
fileSplitterFetch.splitterStop(); /O]t R
D5~n/.B"
pH`44KAuM
} p _d:eZ
} KRjV}\}
//负责部分文件的抓取 4e;QiTj
**FileSplitterFetch.java =}PdH`S
*/ BcD&sQ2F
package NetFox; )]#aauC+
]0L&v7[
xV%6k{_:G
import java.io.*; *!^<m0
import java.net.*; 8BvonYt=8
jNeI2-9c}
h5yzwj:C?
public class FileSplitterFetch extends Thread { :UJa&$)
m~uOXb
y*MF&mQ[
String sURL; //File URL ':R,53tjl
long nStartPos; //File Snippet Start Position 7mm1P9Z
long nEndPos; //File Snippet End Position `gKf#f
int nThreadID; //Thread's ID .k[o$z\EkF
boolean bDownOver = false; //Downing is over x1 1U@jd+1
boolean bStop = false; //Stop identical ["}rk
FileAccessI fileAccessI = null; //File Access interface T)\"Xj
k? Xc
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /t-fjB{=G
{ vd6l7"0/
this.sURL = sURL; H~ u[3LQz
this.nStartPos = nStart; 6=N`wi
this.nEndPos = nEnd; :rP#I#,7w
nThreadID = id; >[6{LAe~hp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?bw4~
} <'G~8tA%v
`-3o+ID\
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public void run() wb Iq&>p
{ c)0amM
while(nStartPos < nEndPos && !bStop) \ u_ui
{ z#F.xVg'
DS|KkTy3
sKyPosnP
try{ fg#x7v4O
URL url = new URL(sURL); ](F#`zUQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -+t]15
httpConnection.setRequestProperty("User-Agent","NetFox"); *%vwM7
String sProperty = "bytes="+nStartPos+"-"; `>o?CIdp
httpConnection.setRequestProperty("RANGE",sProperty); {,OS-g
Utility.log(sProperty); TE )gVE]
`mT$s,:h
9Ct`
InputStream input = httpConnection.getInputStream(); ud fe
//logResponseHead(httpConnection); ddVa.0Z!<
G^"Vo x4
KN"S?i]X
byte[] b = new byte[1024]; T;L>P[hNn
int nRead; hm<}p&!J
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N8`?t5
{ Z0De!?ALV\
nStartPos += fileAccessI.write(b,0,nRead); XlI!{qj|
//if(nThreadID == 1) R}mn*h6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z/rTVAs@r
} #yI.nzA*
PR|R`.QSs
,#W
Utility.log("Thread " + nThreadID + " is over!"); 5<L_|d)0"
bDownOver = true; |y20Hi':
//nPos = fileAccessI.write (b,0,nRead); tRpEF2
} %zU`XVNN+
catch(Exception e){e.printStackTrace ();} =uDgzdDyE
} <}6{{&mT4
} Jgu94.;5
-CH`>
n41@iK2l
//打印回应的头信息 wW?,;B'74
public void logResponseHead(HttpURLConnection con) L !4t[hhe=
{ Q!,<@b)
for(int i=1;;i++) $;G{Pyp
{ /=uMk]h
String header=con.getHeaderFieldKey(i); Vx_rc%'
if(header!=null) f.GETw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a{Esw`
Utility.log(header+" : "+con.getHeaderField(header)); ;IK[Y{W/
else Jx#k,Z4
break; v+"rZ
} '&;yT[
} aQ j*KMc
)EyI0R]5
+jC*'7p@
public void splitterStop() OdI\B
{ ^w~23g.
bStop = true; 9;%CHb&
} *c[2C
t?nX=i*~]
|lH;Fq{\
} j'i0*"x
ZtVAEIZ)
y$hp@m'@C
/* midsnG+jnf
**FileAccess.java TO,rxf
*//文件访问(定位，写) `IINq{Zk
package NetFox; FI8Oz,
import java.io.*; A$g+K,.l
G1 o70
~8|t*@D
public class FileAccessI implements Serializable{ gqib:q;r
W\f9jfD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 avp;*G}
RandomAccessFile oSavedFile; <ktzT&A
long nPos; )x#5Il H
]<DNo&fw
9]$8MY
public FileAccessI() throws IOException ,D6v4<jh
{ m\/(w_/?
this("",0); \bCX=E-
} 8 6QE/M
@+U,Nzd
H(0q6~|
public FileAccessI(String sName,long nPos) throws IOException UkCnqNvx
{ /\mKY%kyh
oSavedFile = new RandomAccessFile(sName,"rw"); zT~B6
this.nPos = nPos; (wRBd
oSavedFile.seek(nPos); =\)IaZ
} /W#O +
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;evCW$G=
public synchronized int write(byte[] b,int nStart,int nLen) 0e["]Tlnm
{ l6[lJ0Y
int n = -1; \F,DA"K_
try{ }W)=@t
oSavedFile.write(b,nStart,nLen); iNCX:Y
n = nLen; v}J;ZIb
} )_zlrX
catch(IOException e) RANPi\]
{ #y]3LC#)^G
e.printStackTrace (); yj@tV2
} [-*F"}D,
~#:e*:ro
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return n; V[pvJ(
} C-P06Q]
c.H?4j7ga
PBks` |+
} RK9>dkW
O}Ui`eWU
VS?@y/\In
/* `29TY&p+"
**SiteInfoBean.java '!vc/Hw
*/ LU!1s@
package NetFox; -'rj&x{Q)U
")s!L"x
d_}a`H
public class SiteInfoBean { HW=xvA+
"C%!8`K{a*
;Hm'6TR!
private String sSiteURL; //Site's URL rqCa 2
private String sFilePath; //Saved File's Path wCZO9sU:6=
private String sFileName; //Saved File's Name QL"gWr`R
private int nSplitter; //Count of Splited Downloading File D_|B2gdZY
hQJWKAf,/
a!Yb1[
public SiteInfoBean() nN`"z3o
{//nSplitter的缺省值为5 w#PZu+
//default value of nSplitter is 5 ZofHic
this("","","",5); U2*6}c<
} `0BdMKjA
a ib}`l
^[h2%c$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2xmk,&s
{ HOYq?40.R
sSiteURL= sURL; 5!fSW2N
sFilePath = sPath; #G_/.h@
sFileName = sName; x;$|#]+
this.nSplitter = nSpiltter; D#sf i,O
].DY"
'\p;y7N
} SqB/4P
m>Ux`Gp+
UFZ"C,
public String getSSiteURL() 24@^{ }
{ 1czG55 |
return sSiteURL; d5xxb _oE
} y[HQBv
*)VAaGUX>
7{BnXN[
public void setSSiteURL(String value) hd^x}iK"
{ vrcE]5(:s
sSiteURL = value; fDuwgY0
} q G;-o)h
\v`#|lT$
^/KfH&E
public String getSFilePath() ';lfS
{ |n P_<9[
return sFilePath; P!\hnm)%4
} lC9S\s
N2~$rpU3
cIw eBDl
public void setSFilePath(String value) ;bHfn-X
{ oXc/#{NC
sFilePath = value; j8HOc(
} [%.18FWI
Gj6. Iv
2:J,2=%
public String getSFileName() KVijs1q
{ hYvNcOSks
return sFileName; BF|*"#s
} 4: sl(r
{vfq
(L#%!bd
public void setSFileName(String value) 1k>naf~O
{ gg8c7d:Q
sFileName = value; GJak.,0t
} AUAI3K?
d7~j^v)=^
9y+[o
public int getNSplitter() NiTJ}1 l
{ )1_(>|@oi
return nSplitter; :GL7J6
} UD*+"~
]V<"(?,K
:o\5K2]:
public void setNSplitter(int nCount) B T7Id
{ "|4jPza
nSplitter = nCount; E/"SU*Co
} ``-k{C#F
} ^g]xU1] *
=x4a~=HX
9--dRTG
/* =h\E<dw
**Utility.java }J;~P 9Y
*/ iBHw[X,b
package NetFox; t{ H1u
STlPT5e.}
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public class Utility { 5+FLSk
oWD)+5.]
7)PJ:4IqS
public Utility() DyX0xx^
{ @KJV1t`
?>)yKa#U
/| f[us-w
} uo 4xnzc
"UpOY
//线程睡眠 ,eK2I Ao
public static void sleep(int nSecond) q2Rf@nt
{ $`Rxn*}V4#
try{ #7C6yXb%
Thread.sleep(nSecond); V2QW\2@$
} JX&~y.F
catch(Exception e) ;Xh5oB\)W
{ [0(mFMC`
e.printStackTrace (); cyb(\ fsC
} \>;%Ji
} &E]"c]i+
<{ #<5 8
//日志 |`v^d|
public static void log(String sMsg) ]Da4.s*mW
{ @SQceQfB
System.err.println(sMsg); R_9 o!sTZ
} =SL^>HS.fo
S| "TP\o
PHl4 vh#E!
public static void log(int sMsg) R25-/6_V>
{ XC}1_VWs
System.err.println(sMsg); :3gFHBFDj
} (k#t}B[
} * 2%oZXF
[U']kt
bQpoXs0w;
/* #8&#E?^d
**TestMethod.java Hi7G/2t@`
*/ 8'%+G
package NetFox; "Y(%oJS]D
]]3Q*bq4
q!@c_o
public class TestMethod { DzE E:&*=
U-ULQ|6U
|QMT A5
public TestMethod() Y}ky/?q
{ ///xx/weblogic60b2_win.exe @QX4 \
try{ 5 Af?Yxv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8ur_/h7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r.Lx%LZ\^
SiteFileFetch fileFetch = new SiteFileFetch(bean); sHF%=Vu
fileFetch.start(); tB!|p6
} gvK"*aIj
catch(Exception e){e.printStackTrace ();} ^:U;rHY
g.=!3e&z%
s1v{~xP
} %27G2^1
H'']J9O
Mi;Tn;3er
public static void main(String[] args) o=@ UXi
{ Hj1k-Bs&'w
new TestMethod(); W >Kp\tD
} s7AI:Zv
} nT)~w s
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