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)); t)!(s,;T
} ,;&j*qFi
for(int i=0;i<nEndPos.length-1;i++) %T~3xQ
{ MBeubS
nEndPos = nStartPos[i+1]; Wu}84W"!.V
} 16J"QUuG
nEndPos[nEndPos.length-1] = nFileLength; 'AU:[eyUV
} %5?Zjp+9
} /0.m|Th'm
A_:CGtv:
DW@|H
//启动子线程 ZGa;'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &xAwk-{W
for(int i=0;i<nStartPos.length;i++) xaPaK-
{ LqZsH0C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yYdow.b!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @N tiT,3k
nStartPos,nEndPos,i); %<^IAMkp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kH.e"e
fileSplitterFetch.start(); ZOAHM1ci
} &nKb<o
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xtWwz}^8]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); WQJnWe
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?M<q95pL
nEndPos = " + nFileLength); 3PLYC}Jq
// fileSplitterFetch[nPos.length-1].start(); 4p}?QR>tZ
0*=[1tdWY
bfE4.YF
//等待子线程结束 {*BZ;Xh\8
//int count = 0; 3xhGmD\SKO
//是否结束while循环 nM<B{AR5^
boolean breakWhile = false; IBT1If3
j aU.hASj
rEoMj)~\4&
while(!bStop) i9RAbtQ}
{ (aeS+d x
write_nPos(); ro%Jg
Utility.sleep(500); l;~b:[r
breakWhile = true; s*g`| E{M
4X}.aZO&b
=._V$:a6o
for(int i=0;i<nStartPos.length;i++) ~W>3EJghR,
{ A$7j B4
if(!fileSplitterFetch.bDownOver) HQy:,_f@
{ cF2!By3M
breakWhile = false; ++gWyzD
break; 762c`aP_(
} 6E)emFkQ
} TJO?BX_9
if(breakWhile) rk E;OU
break; iAl.(j
j;7:aM"BQW
D\4pLm"!v
//count++; Pg''>6w>
//if(count>4) hy]8t1894
// siteStop(); 0XSMby?t`
} ` P,-NVB
"9^OT
(zmLMG(R
System.err.println("文件下载结束！"); : Yb_
} 2]UwIxzR
catch(Exception e){e.printStackTrace ();} !*\J4bJe
} "Dt: 8Nf^
Q"Pl)Q\
x@p1(V.
//获得文件长度 u]766<Z
public long getFileSize() ]YciLc(
{ KHTRoXt
int nFileLength = -1; >7$h
try{ H#+2l?D:"
URL url = new URL(siteInfoBean.getSSiteURL()); EK%J%NY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~_]i'ii8
httpConnection.setRequestProperty("User-Agent","NetFox"); 3nbTK3,
ty>9i]Y-
N hY`_?)
int responseCode=httpConnection.getResponseCode(); GzN /0:b
if(responseCode>=400) a !yBEpMo
{ hU~up a<dD
processErrorCode(responseCode); =^5#o)~BB
return -2; //-2 represent access is error d%~OEq1i"
} 1)BIh~1{p
N|3a(mtiZ'
J?$`Tnx^
String sHeader; J5zKwt
kZK1{
KlGmO;k
for(int i=1;;i++) 84g8$~M
{ BGrV,h^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ] :.
//Utility.log(in.readLine()); r}4
sHeader=httpConnection.getHeaderFieldKey(i); e`eh;@9p
if(sHeader!=null) <*@!>6mS
{ GTocN1,Z~a
if(sHeader.equals("Content-Length")) 5{|tE!
{ ,GYK3+}Z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .P(Ax:g
break; ~5;2ni8n
} 9zD,z+
} ?~9o2[
else f~R`RBZ]9
break; iGw\A!}w\
} ,opS)C$
} l|S_10x5
catch(IOException e){e.printStackTrace ();} }08Sv=XM
catch(Exception e){e.printStackTrace ();} (o2.*x
d9.I83SS
nhLw&V3y
Utility.log(nFileLength); _x]q`[Dih
FwpTQix!
q71V]!
return nFileLength; m0,TH[HWGF
} *s%M!YM
HXP/2&|JY
9zNMv-
//保存下载信息（文件指针位置） Z&6*8#wn
private void write_nPos() Rebo.6rG
{ G\B:iyKl
try{ Vif)e4{Pn
output = new DataOutputStream(new FileOutputStream(tmpFile)); bcUa'ZfN<
output.writeInt(nStartPos.length); ?hOvY)
for(int i=0;i<nStartPos.length;i++) `G<|5pe
{ |H'wDw8
// output.writeLong(nPos); H03R?S9AQ
output.writeLong(fileSplitterFetch.nStartPos); , D}
output.writeLong(fileSplitterFetch.nEndPos); *EF`s~
} 4Jk[X>I~
output.close(); o<L=l Q
} KSR'X0'
catch(IOException e){e.printStackTrace ();} axM(3k.n
catch(Exception e){e.printStackTrace ();} D"<>!]@(a
} @0D
o(@^V!}V
]?k\ qS
//读取保存的下载信息（文件指针位置） {S"!c.
private void read_nPos() |!xqkmX
{ gCZm7dgo
try{ j|IvDrm#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uX8G<7O^
int nCount = input.readInt(); *d}{7UMy#
nStartPos = new long[nCount]; '^`%
nEndPos = new long[nCount]; | W<jN
for(int i=0;i<nStartPos.length;i++) r}|a*dh'R
{ 5iZ;7 ?(
nStartPos = input.readLong(); y:VY8a 4
nEndPos = input.readLong(); o>y@1%aU
} dG%{&W9
input.close(); I6Oc`S!L
} 0F%V+Y\R
catch(IOException e){e.printStackTrace ();} qFwAzW;"
catch(Exception e){e.printStackTrace ();} !4}Wp.
} HEs.pET\
#OsUF,NU
-f=4\3y3p
private void processErrorCode(int nErrorCode) g)=-%n'RoE
{ BUU ) Sz
System.err.println("Error Code : " + nErrorCode); #F:\_!2c
} 4=ZN4=(_[
tREC)+*\
hEfFMi=a`
//停止文件下载 S*(ns<L
public void siteStop() ngl8) B
{ ?dQ#%06mn
bStop = true; ^dRgYi"(A
for(int i=0;i<nStartPos.length;i++) wQrD(Dv(yA
fileSplitterFetch.splitterStop(); RO.bh#A$
!UX7R\qu|
FK,Jk04on
} dRXdV7-!
} x}jiHV@=
//负责部分文件的抓取 'ExTnv ~
**FileSplitterFetch.java ;f~z_3g
*/ Z]k+dJ[-
package NetFox; vU!<-T#
V w5@)l*f
(lLCAmK5?
import java.io.*; '9Xw_1B
import java.net.*; H 2UR
k^Uk=)9
~.<}/GP]_
public class FileSplitterFetch extends Thread { v$EgVcK
"xE;IpO[
Ov|Uux
String sURL; //File URL m.>y(TI
long nStartPos; //File Snippet Start Position )Zit6I
long nEndPos; //File Snippet End Position W%P0X5YQ
int nThreadID; //Thread's ID !K/zFYl
boolean bDownOver = false; //Downing is over z1~FE
boolean bStop = false; //Stop identical Y[`%j\=
FileAccessI fileAccessI = null; //File Access interface j(`V&S
ZN-5W|' O
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~n9-
{ ul ag$ge
this.sURL = sURL; <UBB&}R0
this.nStartPos = nStart; AGgL`sP
this.nEndPos = nEnd; -LMO f[v?
nThreadID = id; .6y(ox|LL
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k+As#7V
} tzSg`7H!
?KXgG'!!
b`X"yg+
public void run() Iw;J7[hJ&$
{ 5JA5:4aev
while(nStartPos < nEndPos && !bStop) o3xfif
{ P:tl)ob
bPo*L~xdk
H_+!.
try{ \&1Di\eL
URL url = new URL(sURL); YLe$Vv735
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Mf.:y
httpConnection.setRequestProperty("User-Agent","NetFox"); XjV,wsZ=
String sProperty = "bytes="+nStartPos+"-"; O-YB+~"3Z
httpConnection.setRequestProperty("RANGE",sProperty); ]5hGSl2
Utility.log(sProperty); zoO9N oUHW
~riV9_-
.5YIf~!59
InputStream input = httpConnection.getInputStream(); P1}Fn:Xe%7
//logResponseHead(httpConnection); b}5hqIy
'3V?M;3|K
o_DZ
byte[] b = new byte[1024]; 9lCZi?
int nRead; ,L,?xvWG
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zFGZ;?i
{ +]NPxUa
nStartPos += fileAccessI.write(b,0,nRead); 6$"0!fl>
//if(nThreadID == 1) AHtLkfr(r
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q7@ m.w%`
} <aEY=IF4
oB]
z\Y-8a.]
Utility.log("Thread " + nThreadID + " is over!"); /Jw65 e
bDownOver = true; 4e55
//nPos = fileAccessI.write (b,0,nRead); uZ7~E._
} ziBg'
catch(Exception e){e.printStackTrace ();} L?p,Sy<RI
} _b1w<T `
} Bi|XdS$G
Kh;jiK !
@Zd/>'
//打印回应的头信息 ZsikI@?
public void logResponseHead(HttpURLConnection con) iv]*HE
{ *C n `pfO
for(int i=1;;i++) jM DG
{ wa}\bNKQk
String header=con.getHeaderFieldKey(i); om'DaG`A
if(header!=null) +:fr(s!OE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); rezH5d6z62
Utility.log(header+" : "+con.getHeaderField(header)); =;"$t_t
else #{u>
break; @x z?^20N
} Z )f\^
} FtL{f=
}I;5yk,o
><Z`)}f
public void splitterStop() ;p}X]e l}
{ D/= AU
bStop = true; auP6\kpMe
} GMO|A.bzzN
.|g67PH=
A(>kp=~
} ]jL`*tI\S
3d0Yq
Q #%C)7)
/* @hE$x-TP0
**FileAccess.java HX]pcX^K
*//文件访问(定位，写) umD[4aP~;
package NetFox; A&~<qgBTp
import java.io.*; E6NrBPm
>9v?p=
(ON_(MN
public class FileAccessI implements Serializable{ j.L`@
D3+UV+&R/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xRx8E;Q@h?
RandomAccessFile oSavedFile; EL[N%M3
long nPos; .g6DKjy>
M~1 n#
DlXthRM
public FileAccessI() throws IOException :U7m@3czU
{ P_f>a?OL:
this("",0); 5wws8w
} ;f8$vW];
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/:j9#kj
public FileAccessI(String sName,long nPos) throws IOException 8v)PDO~D}A
{ uJP9J U
oSavedFile = new RandomAccessFile(sName,"rw"); `RG_FS"v
this.nPos = nPos; &E>zvRBQ
oSavedFile.seek(nPos); 8I'Am"bc\
} q3s +?&
t,2Q~ied=
faVR %
public synchronized int write(byte[] b,int nStart,int nLen) j`9+pI
{ MFyMo
int n = -1; z!={d1u#T
try{ @fH?y Z=>
oSavedFile.write(b,nStart,nLen); kM`!'0kt
n = nLen; !y>MchNv
} \5wC&|WEB
catch(IOException e) :%?\Wj5HW
{ |$vhu`]Z@^
e.printStackTrace (); I=,u7w`m
} ,DT=(
cQaEh1n
W~1MeAI
return n; GoGo@5n(Z
} i*JbFukG
Q7]VB p4
}Dig'vpMx
} btC.EmX
1z\>>N$7B
T F!Lp:
/* IJ%S[>
**SiteInfoBean.java jJjD)
*/ *Iu .>nw
package NetFox; ZhWtY
# Z*nc0C
a?IL6$z
public class SiteInfoBean { Bpjwc<U
J@{yWgLg
$cLtAo^W
private String sSiteURL; //Site's URL S;"7d
private String sFilePath; //Saved File's Path .kT5 4U;{
private String sFileName; //Saved File's Name A|BvRZd
private int nSplitter; //Count of Splited Downloading File nx(O]R,Sw
L}&U%eD
}xl @:Qo
public SiteInfoBean() nJTV@mXVq
{//nSplitter的缺省值为5 .>-`2B*/
//default value of nSplitter is 5 GB+U>nf
this("","","",5); *q%)q
} VxOrrs7Z
&\\iD :J
x0])&':!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `nO!_3
{ S?}@2[
sSiteURL= sURL; RN?z)9!
sFilePath = sPath; iz`u@QKc%
sFileName = sName; a; Ihv#q
this.nSplitter = nSpiltter; 89B1\ff
`'u|4pRFs
:B=p%C
} '\:?FQ C
/hue]ZaQq
IkSzjXE{
public String getSSiteURL() t/,k{5lX
{ Cm;WQuv@
return sSiteURL; 8KpG0DC
} z,nRw/o
~>@Dn40
-v9V/LJ
public void setSSiteURL(String value) `@{qnCNQ
{ @|&P#wd.u
sSiteURL = value; *xs8/?
} ~BVg#_P
7 :s6W%W1*
DTdL|x.{
public String getSFilePath() _Y*: l7
{ cI3uH1;#
return sFilePath; z(^p@&r)F
} U~SK 'R
A+j~oR
AZ5c^c)
public void setSFilePath(String value) #Dx$KPD
{ bwo"s[w
sFilePath = value; O'deQq[
} :L9\`&}FS
(jkjj7a
}k}5\%#li5
public String getSFileName() J4te!,
{ 8zz-jkR
return sFileName; 0Bn$C,-
} MB\vgKY
:Ke~b_$Uy-
xH\'gli/
public void setSFileName(String value) \O?#gW\tR
{ kX{c+qHM
sFileName = value; ~K^Z4
} &hs)}uM&$
GZ@!jF>!u
knypSgk_
public int getNSplitter() K:P gkc
{ bTKzwNx
return nSplitter; '<m[
} 9Dd/g7
}6eWdm!B
n$}c+1
public void setNSplitter(int nCount) a2iaP
{ jHB,r^:'
nSplitter = nCount; f7XmVCz1
} p`{9kH1me
} $,icKa
[HIg\N$I8C
k+-u4W
/* 6R@ v>}
**Utility.java G\TyXq_4
*/ 8Md*9E#J("
package NetFox; <"CG%RGP
=Ze~6vS,
%Q}#x
public class Utility { Jx_ OT C
hW>@jT"t1C
Kd;|Z
public Utility() qX:54$t
{ g<KBsz!{
Czb@:l%sc
P 2;j>=W
} &#g;=jZ
ep[7#\}5
//线程睡眠 SL:o.g(>4
public static void sleep(int nSecond) ?{cF'RB.
{ !e.@Xk.P6
try{ 34]f[jJ|
Thread.sleep(nSecond); ZWmmFKFG.
} BWL~)Hx
catch(Exception e) qVJV9n
{ J_U1eSz<j
e.printStackTrace (); Cb.~Dv !
} y"!+Fus9
} V}7I? G
ngEjbCV+
//日志 "v jFL9
public static void log(String sMsg) yBauK-7*c
{ N+!{Bt*
System.err.println(sMsg); {:od=\*R
} 8!me$k&
D4n~2]
]Rnr>_>x;
public static void log(int sMsg) Z'WoChjM
{ ;{BELv-4
System.err.println(sMsg); 2={`g/WeE
} u;~/B[
} sEe^:aSN
<J{VTk ~
GIo&zPx
/* 5x4JDaG2
**TestMethod.java E+>Qpy
*/ z{``v|K
package NetFox; 6!Ji-'\"
;2)@NH
t1g)Y|@d
public class TestMethod { A(Ugam~}
F7#
bPOehvK/
public TestMethod() -`iZBC50
{ ///xx/weblogic60b2_win.exe 5ah]E
try{ o*I=6`j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); TS$ 2K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q>JJI:uC4
SiteFileFetch fileFetch = new SiteFileFetch(bean); :%xiH%C>
fileFetch.start(); gHvxmIG
} 6/.-V1*O
catch(Exception e){e.printStackTrace ();} ?$pp%
U $X"W'
id&;
} [)#,~L3
J'b*^K
7DKbuUK
public static void main(String[] args) W84JB3p
{ y&-j NOKLM
new TestMethod(); EmVE<kY.
} "ln(EvW
} )@\= pE.H
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