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)); J!:v`gb#@A
} mZ.E;X& ,*
for(int i=0;i<nEndPos.length-1;i++) wQU-r|
{ r]%.,i7~8
nEndPos = nStartPos[i+1]; 30h1)nQ$h}
} TzrU |D?
nEndPos[nEndPos.length-1] = nFileLength; yjucR Fl
} ^Y^5 @x=
} NmV][0(BS
HgRfMiC
]2xoeNF/W{
//启动子线程 BtP*R,>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [,qb) &_
for(int i=0;i<nStartPos.length;i++) mh~n#bah
{ cx4'rK.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0.!Q4bhD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5O"wPsl
nStartPos,nEndPos,i); uzLIllVX*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7 P]Sc
fileSplitterFetch.start(); +e)RT<
} dYhLk2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]GPUL>7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Q$2^m(?;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |)Sx"B)
nEndPos = " + nFileLength); $]iRfXv,l!
// fileSplitterFetch[nPos.length-1].start(); XXZ$^W&
~{s7(^ P
Pl[WCh
//等待子线程结束 #e;\Eap
//int count = 0; 7033#@_
//是否结束while循环 e7gWz~
boolean breakWhile = false; b"z9Dpv
1H,hw
P C
while(!bStop) ,6a }l;lv
{ d*<goBd
write_nPos(); U_e e3KKA
Utility.sleep(500); +yu^Z*_
breakWhile = true; f%Bmx{Ttq
_Y,d|!B#L
evHKq}{
for(int i=0;i<nStartPos.length;i++) wB W]w
{ veGRwir
if(!fileSplitterFetch.bDownOver) ]ipltR7k
{ {~:F1J~=
breakWhile = false; 5>[j^g+@
break; >a1ovKF
} g,cl|]/\d
} h3:dO|Z
if(breakWhile) |CjE}5Op>
break; 'D;'Pr]
dKTUW<C
p uLQ_MNV
//count++; ;/-#oW@gQ
//if(count>4) `F1 ( v
// siteStop(); kzb1iBe 6m
} iG;GAw|E
We,~P\g
j!<RY>u
System.err.println("文件下载结束！"); ^aO\WKkA
} r`(U3EgP
catch(Exception e){e.printStackTrace ();} 18U CZ;)>
} GPnSdGLC
FzGla})
ZN?UkFnE
//获得文件长度 ;}gS8I|
public long getFileSize() tvG/oe .1'
{ FqK2[]8
int nFileLength = -1; ZX!u\O|w
try{ L`{EXn[
URL url = new URL(siteInfoBean.getSSiteURL()); s"\o6r ,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S}cm.,/w
httpConnection.setRequestProperty("User-Agent","NetFox"); o\YF_235
6?c(ueiL[
I~>L4~g)
int responseCode=httpConnection.getResponseCode(); M0zlB{eH
if(responseCode>=400) /0H39]y!~
{ A">A@`}
processErrorCode(responseCode); -!]dU`:(X
return -2; //-2 represent access is error :S5B3S@|
} D;al(q
_*Z2</5
jVpk) ;vC
String sHeader; !]k$a
3_tO
i3} ^j?jA2
for(int i=1;;i++) ]gQ4qu5
{ ,fwN_+5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?pv}~>
//Utility.log(in.readLine()); DHV#PLbN$
sHeader=httpConnection.getHeaderFieldKey(i); V OViOD
if(sHeader!=null) U8(Rye$
{ )d6Ya1vJH
if(sHeader.equals("Content-Length")) PDcZno?
{ K}U}h>N
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bh1WD_
break; 5? s$(Lt~
} V/G'{ q
} {^#62Y
else x1kb]0s<-
break; j5:{H4?
} XK>/i}y
} ivbuS-f=r
catch(IOException e){e.printStackTrace ();} Whq@>pX8
catch(Exception e){e.printStackTrace ();} jo4*,B1x
_KkLH\1g$
2|)3Ly9
Utility.log(nFileLength); FPu"/4v&
=,~h]_\_
98os4}r
return nFileLength; D`lTP(] y
} MD,}-m
)[>b7K$f
M"]~}*
//保存下载信息（文件指针位置） mq?5|`
private void write_nPos() RYaf{i`
{ <Dw`Ur^X5
try{ !RnO{FL
output = new DataOutputStream(new FileOutputStream(tmpFile)); p_jDnb#
output.writeInt(nStartPos.length); !ldb_*)h
for(int i=0;i<nStartPos.length;i++) zZ|Si
{ r c7"sIkV
// output.writeLong(nPos); qlSc[nEk
output.writeLong(fileSplitterFetch.nStartPos); \dbjh{
output.writeLong(fileSplitterFetch.nEndPos); Q+[e)YO)
} XX,iT~+-
output.close(); 0*"auGuX
} XnQo0 R.PW
catch(IOException e){e.printStackTrace ();} 0f 1Lu) 2
catch(Exception e){e.printStackTrace ();} g@.RfX=
} #"a?3!wr
H85HL-{
x(z[S$6Y\
//读取保存的下载信息（文件指针位置） ~3.1. 'A
private void read_nPos() S"UFT-N
{ +xwz.:::
try{ ho_;;y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5yO6szg
int nCount = input.readInt(); j3rBEQ,R
nStartPos = new long[nCount]; o)7gKWjujP
nEndPos = new long[nCount]; A:EF#2)g
for(int i=0;i<nStartPos.length;i++) tZ[Y~],F
{ PY.c$)az>
nStartPos = input.readLong(); $Tt@Xu
nEndPos = input.readLong(); 8ltHR]v
} AyKaazm]9
input.close(); #{GUu',?&
} Z xLjh
catch(IOException e){e.printStackTrace ();} l,*v/95h
catch(Exception e){e.printStackTrace ();} 3C8'0DB
} rO/mK$
>'/G:\M>A
y5.Z<Y
private void processErrorCode(int nErrorCode) G|yX9C]R
{ Mu18s}
System.err.println("Error Code : " + nErrorCode); glh2CRUj
} "';'*x
z_eP
5,'?NEyw
//停止文件下载 b1jh2pG(V
public void siteStop() 0i9y-32-
{ E)>~0jv
bStop = true; G.O0*E2V
for(int i=0;i<nStartPos.length;i++) 0,(U_+n
fileSplitterFetch.splitterStop(); -@G|i$!
rB}UFS)
Gu<3*@Ng
} I~MBR2$9
} [zK|OMxoV
//负责部分文件的抓取 hZ.Sj~>7`
**FileSplitterFetch.java %L{H_;z
*/ j_\sdH*r
package NetFox; 'bkecC
t(CdoE,6
Lm9y!>1"O
import java.io.*; $GUSTV
import java.net.*; XZA3TZ
3~BL!e,
&TSt/b/+W
public class FileSplitterFetch extends Thread { -[v:1\Vv
R5G~A{w0
Y*3qH]
String sURL; //File URL }3Pz{{B&+O
long nStartPos; //File Snippet Start Position ;'dw`)~jQ
long nEndPos; //File Snippet End Position &Hc8u,|
int nThreadID; //Thread's ID bc5+}&W
boolean bDownOver = false; //Downing is over ";9cYoKRY
boolean bStop = false; //Stop identical +}>whyX1
FileAccessI fileAccessI = null; //File Access interface ?{$Q'c_I
`ItMn&P
U}6'_ PRQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {Zjnf6d]
{ |v}"UW(y
this.sURL = sURL; tz&=v,_jc
this.nStartPos = nStart; z['>`Kt
this.nEndPos = nEnd; *4r 1g+0
nThreadID = id; ];^A8?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RM-|?%
} `Ten2(D
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k _hiGg
public void run() rZe"*$e
{ IO`.]iG
while(nStartPos < nEndPos && !bStop) ,y3o ,gl
{ 57)S"
vAq`*]W+
$uawQf+S
try{ D<#+ R"
URL url = new URL(sURL); `.Y["f 1B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e\k=T}
httpConnection.setRequestProperty("User-Agent","NetFox"); 7<AHQ<#@
String sProperty = "bytes="+nStartPos+"-"; t'_Hp},
httpConnection.setRequestProperty("RANGE",sProperty); Z~~{!C+G
Utility.log(sProperty); DL|,:2`
A(W%G|+
<dD}4c+/t
InputStream input = httpConnection.getInputStream(); WDSkk"#TF
//logResponseHead(httpConnection); wQ*vcbQX*
3otia;&B
v@LK3S/!3
byte[] b = new byte[1024]; >yg mE`g
int nRead; yVUA7IY
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `z-4OJ8~
{ 7NMQUN7k'
nStartPos += fileAccessI.write(b,0,nRead); ~o= Sxaf
//if(nThreadID == 1) {IYfq)c
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $=4T# W=m
} Bra>C
wZh&w<l'
%(Nu"3|$K=
Utility.log("Thread " + nThreadID + " is over!"); ._~_OVU
bDownOver = true; 1SP)`Q
//nPos = fileAccessI.write (b,0,nRead); 234OJ?
} j@v*q\X&
catch(Exception e){e.printStackTrace ();} IaH8#3+a
} C&,&~^_F
} #!OCEiT_
KFdV_e5lU
nyi}~sB
//打印回应的头信息 Av^{$9yl
public void logResponseHead(HttpURLConnection con) 3p"VmO
{ h$DFp
for(int i=1;;i++) OlK3xdg7
{ ~+A?!f;-J
String header=con.getHeaderFieldKey(i); 2Auhv!xV
if(header!=null) gtyo~f
//responseHeaders.put(header,httpConnection.getHeaderField(header)); MmI4J$F
Utility.log(header+" : "+con.getHeaderField(header)); pB&3JmgR$)
else Nlx7"_R"Q
break; JaXT B"e
} 75r>~@)*
} VljAAt
Ha@'%<gFe
sk\U[#ohH
public void splitterStop() '~VKH}b
{ %UI.E=`n
bStop = true; Lz2wOB1Zc+
} *j?tcxq
?!U=S=8
u&/q7EBfP
} l{>fma]7
4vT!xn
8s/gjEwA
/* r )ZUeHt}w
**FileAccess.java GRB/N1=
*//文件访问(定位，写) `$ZX]6G
package NetFox; Y|_#yb
import java.io.*; MGfDxHg]
,G!M?@Q
81eDN6 M\
public class FileAccessI implements Serializable{ FAfk;<#'n+
V8ZE(0&II}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 wdS^`nz|
RandomAccessFile oSavedFile; );_g2=:#
long nPos; ]@Y8! ,
b4Br!PL@G
!jN}n)FSq
public FileAccessI() throws IOException G+stt(k:
{ mp!KPw08':
this("",0); <{bQl L
} U s86.@|
klxVsx%I{G
f_}/JF
public FileAccessI(String sName,long nPos) throws IOException ];Z)=y,vM
{ <gF=$u|}3[
oSavedFile = new RandomAccessFile(sName,"rw"); P9p:x6
this.nPos = nPos; !Y>lAxd
oSavedFile.seek(nPos); "CLoM\M)
} KtchKpv
=dx!R ,Bw
_Db=I3.HJ
public synchronized int write(byte[] b,int nStart,int nLen) CL.JalR`b
{ K#rfQ0QK/!
int n = -1; OSQZ5:g|
try{ S<rdPS*P
oSavedFile.write(b,nStart,nLen); au@ LQxKQ
n = nLen; ,;)Y1q}Q
} }l~|c{WH`
catch(IOException e) Zk4Hs%n
{ GR@!mf
e.printStackTrace (); 7cW9@xPe
} N+ZDQa[
)uC],CbW{
#qrZ(,I@n
return n; 6!dbJ5x1
} ^E\{&kaUp
<nlZ?~%}
L`;p.L Bs_
} 3XF.$=@
R''nZ/R
M.$Li#So,
/* g@wF2=
**SiteInfoBean.java qYR $5
*/ N-`Vb0;N
package NetFox; "RMBV}<T
>/mi#Y6
D9,609w
public class SiteInfoBean { {*,~,iq
"X0"=1R~
Oo|*q+{
private String sSiteURL; //Site's URL w F6ywr
private String sFilePath; //Saved File's Path v,y nz'>)
private String sFileName; //Saved File's Name '?=SnjMX
private int nSplitter; //Count of Splited Downloading File L9Sd4L_e
W2/FGJD
#N^TqOr
public SiteInfoBean() \95qH,w)T
{//nSplitter的缺省值为5 =F'p#N0_2
//default value of nSplitter is 5 -1iKeyyA
this("","","",5); hTcy;zLLS
} =+5z;3
A]ZCQ49
QA>(}u\+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =y-L'z&r
{ M4 SJnE
sSiteURL= sURL; Cw42bO
sFilePath = sPath; 7K.&zn
sFileName = sName; J!5BH2bg
this.nSplitter = nSpiltter; U/F<r3.`#
_OV\W'RrA
w}No ^.I*4
} u$ C@0d
=sy>_
@Gp=9\L
public String getSSiteURL() x{{QS$6v
{ !$Aijd s5
return sSiteURL; ]T|9>o!
} Xou1X$$z
[p[nK=&r
j(^ot001%v
public void setSSiteURL(String value) (Cjnf a 2
{ e9e%8hL
sSiteURL = value; KiW4>@tY
} e~R; 2bk
.{sKEVK
*z[G+JX
public String getSFilePath() XndGe=O
{ >2h|$6iWP
return sFilePath; X8~dFjhX
} *uHL'Pe;m
uo0g51%9
,:g.B\'Q
public void setSFilePath(String value) $$ %4,\{l
{ y_O[r1MF
sFilePath = value; 5tPBTS<<"L
} {Hncm
:VwU2
xg=}MoX
public String getSFileName() 2VmQ%y6e"
{ =B4,H=7Spf
return sFileName; HUqG)t*c1
} Oop5bg
VD[x}8ei
jv$Y]nf
public void setSFileName(String value) RtVy^~=G
{ r/v'h@
sFileName = value; <;O=h; ~|
} ]=\Mf<
#oRm-yDr
)E;+C2G
public int getNSplitter() zogtIn)
{ Ow7NOhw
return nSplitter; RC7|@a
} *Q2;bmIc
C!Cg.^;
9~+A<X]Hd
public void setNSplitter(int nCount) 7sP;+G
{ O7@CAr
nSplitter = nCount; Eu/~4:XN
} 6k6M&a
} / hUuQDJ
5G.Fi21 b
Bz}Dgbb
/* a*LT<N
**Utility.java u] C/RDTH
*/ TymE(,1
package NetFox; hUirvDvX
q6A!xQs<
9pPb]v,6
public class Utility { 6o@}k9AN
89@\AjI
8N<0|u
public Utility() W{E22J}
{ Pn@k)g
%bI(
Rz}?@zh_8
} n}==
\PS{/XK
//线程睡眠 M99#\0=/
public static void sleep(int nSecond) i`o}*`//
{ ?DcRD)X
try{ xe^*\6Y
Thread.sleep(nSecond); x_9<&Aj6
} *8}Y0V\s
catch(Exception e) #PnuR2s7.
{ S,T?(lSl
e.printStackTrace (); }* iag\
} ?wE@9g A
} Zu(eYH=Q
8@%Xd^
//日志 [% chN/
public static void log(String sMsg) }Ictnb
{ "=4`RM
System.err.println(sMsg); HZMs],GX
} QX(x6y>Q
#.O,JG#H
:T~Aa(%(
public static void log(int sMsg) $q*kD#;mh
{ Hj ]$
System.err.println(sMsg); PoMkFG6
} ps0wN%tA
} f`<j(.{9F
$iQ>c6
}*Qd]\fy
/* @C)O[&Sk
**TestMethod.java lhg3 }dW
*/ tB.;T0n
package NetFox; =jD[A>3I
RAR0LKGX
A7U'>r_.
public class TestMethod { CG'NC\x5
R`=3lY;
3nuf3)
public TestMethod() 5zJkPki
{ ///xx/weblogic60b2_win.exe VlW#_.
try{ Hv%(9)-8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `NA[zH,w3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z&8 7Aj
SiteFileFetch fileFetch = new SiteFileFetch(bean); GF~^-5
fileFetch.start(); *nNzhcuR
} -oq!zi4:
catch(Exception e){e.printStackTrace ();} 4mOw[}@A
}C>Q
1"46OCu{
} 9dA(f~
.lu:S;JSnS
PK1j$&F
public static void main(String[] args) J*6I@_{/U
{ E%eao$
new TestMethod(); 3ojK2F(1D
} 1wUZ0r1'
} Cw?AP6f%
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