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)); rEz^
} :NTO03F7v
for(int i=0;i<nEndPos.length-1;i++) `N8O"UcoBo
{ A?OQE9'
nEndPos = nStartPos[i+1]; &_8947
} }"%N4(Kd
nEndPos[nEndPos.length-1] = nFileLength; M&M6;Ph
} _ jlRlt
} P@~yx#G
7tCw*t$
goWuw}?
//启动子线程 2y1Sne=<Kb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; HTTCTR
for(int i=0;i<nStartPos.length;i++) % |L=l{g
{ `){.+S(5C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %E;'ln4h&,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Qn2&nD%zi
nStartPos,nEndPos,i); buHJB*?9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q22 GIr
fileSplitterFetch.start(); +&H4m=D-#a
} K3l95he
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), es0hm2HT3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); sV*H`N')S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hOK8(U0
nEndPos = " + nFileLength); n~Lt\K:
// fileSplitterFetch[nPos.length-1].start(); ]T) 'Hb
_DEjF)S
z`b,h\
//等待子线程结束 7F.4Ga;
//int count = 0; %A0/1{(
//是否结束while循环 >^{yF~(
boolean breakWhile = false; j_j]"ew)
j B{8u&kz)
>=w)x,0yX
while(!bStop) 9+!hg'9Qn
{ :[d9tm
write_nPos(); /G`]=@~
Utility.sleep(500); K)iF>y|{*q
breakWhile = true; WTiD[u
a?oI>8*
&uVnZ@o42
for(int i=0;i<nStartPos.length;i++) hXya*#n#
{ 5#z1bu
if(!fileSplitterFetch.bDownOver) ZYNsHcTY
{ +aAc9'k
breakWhile = false; 0<*<$U
break; :Llb< MY2
} 3PF_H$`oJ
} V|R,!UND
if(breakWhile) (^>J&[=
break; B`sAk %
?gXp*>Kg[
1{.9uw"2S
//count++; pTuS*MYz
//if(count>4) QTnP'5y
// siteStop(); ksm~<;td
} ,`sv1xwd
iN.n8MN=I
$<OD31T
System.err.println("文件下载结束！"); tQ601H>o
} eszG0Wu
catch(Exception e){e.printStackTrace ();} 43 :X,\~)
} 1xx}~|F?|
1B\WA8
0tJZ4(0
//获得文件长度 tT._VK]o&R
public long getFileSize() Ew$C ;&9
{ o#N+Y?O
int nFileLength = -1; @'|~v<<WZ
try{ 6wg^FD_Q
URL url = new URL(siteInfoBean.getSSiteURL()); f?)-}\[IR{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J9 I:Q<;
httpConnection.setRequestProperty("User-Agent","NetFox"); _','9|
{\\Tgs
U%/+B]6jP
int responseCode=httpConnection.getResponseCode(); -ze J#B)C
if(responseCode>=400) R^e'}+Z
{ K.yb ^dg5
processErrorCode(responseCode); &,)&%Sg[
return -2; //-2 represent access is error IvNT6]6 P
} iJ|uvPCE
K|s,ru
,tRj4mx
String sHeader; fd9k?,zM
L\iFNT}g`
VG~Vs@c(
for(int i=1;;i++) KG{St{uJ
{ lr$zHI7_`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N)Z?Z+}h
//Utility.log(in.readLine()); EBmt9S
sHeader=httpConnection.getHeaderFieldKey(i); nT)vNWT=
if(sHeader!=null) EEL,^3KR
{ B|X!>Q<g
if(sHeader.equals("Content-Length")) -%4,@ x`
{ {7pli{`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D3K8F@d
break; ~bpgSP"
} r@,2E6xn
} ]]Ufas9
else %N_%JK\{@
break; {fp[BF
} |gY^)9ei
} 8a"%0d#
catch(IOException e){e.printStackTrace ();} xe$_aBU
catch(Exception e){e.printStackTrace ();} ,"0:3+(8;
Q=dy<kg']
S5EK~#-L[
Utility.log(nFileLength); ?Ss!e$jf
]J]h#ZHx
{(?4!rh
return nFileLength; pmYHUj #
} QSf|nNT
+qdEq_m
3T0"" !Q
//保存下载信息（文件指针位置） f|oh.z_R
private void write_nPos() f`66h M[
{ < FAheE+
try{ p{dj~ &v
output = new DataOutputStream(new FileOutputStream(tmpFile)); GsM<2@?
output.writeInt(nStartPos.length); 0C,`h`
for(int i=0;i<nStartPos.length;i++) ,MIV=*
{ 7Fsay+a
// output.writeLong(nPos); @9|hMo
output.writeLong(fileSplitterFetch.nStartPos); ] @fk]]R
output.writeLong(fileSplitterFetch.nEndPos); |(^PS8wG
} f6"Z'{j
output.close(); | VDV<g5h
} IO:G1;[/2L
catch(IOException e){e.printStackTrace ();} Y\'}a+:@Ph
catch(Exception e){e.printStackTrace ();} +x}<IS8
} ?|Zx!z ($
X#;bh78&-
UJ6v(:z<
//读取保存的下载信息（文件指针位置） o#1 $q`Z
private void read_nPos() 1[-tD0{H
{ El"Q'(:/U
try{ '@P^0+B!(.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); FHI ;)wn=
int nCount = input.readInt(); lsNd_7k
nStartPos = new long[nCount]; 3"\lu?-E
nEndPos = new long[nCount]; 8DaL,bi*.
for(int i=0;i<nStartPos.length;i++) \Y}8S/]
{ R@rBEW&
nStartPos = input.readLong(); @"H>niG
nEndPos = input.readLong(); QkC(uS
} @7n"yp*"
input.close(); IIx#2r
} L_iFt!
catch(IOException e){e.printStackTrace ();} Q&bM\;Ml
catch(Exception e){e.printStackTrace ();} y"wShAR
} Pk)1WK7E
QP J4~
\dQNLLg/
private void processErrorCode(int nErrorCode) geCM<]
{ 8}| (0mC
System.err.println("Error Code : " + nErrorCode); r]36zX v
} jrh43 \$*
v/=}B(TDF
Ooy7*W';
//停止文件下载 jo@J}`\Zt
public void siteStop() jW@Uo=I[
{ *-p}z@8
bStop = true; Mf``_=K
for(int i=0;i<nStartPos.length;i++) uu687|Pm
fileSplitterFetch.splitterStop(); H$4:lH&(
h9W^[6
/&94 eC
} ,zY$8y]
} 'uEl~> l7
//负责部分文件的抓取 2jhxQL
**FileSplitterFetch.java 1|wL\I
*/ $E.I84UfX
package NetFox; N87B8rDl
?FcAXA/J{
czd~8WgOa
import java.io.*; h'F=YF$o
import java.net.*; !C:$?oU
|$b}L7_
ekCC5P!
public class FileSplitterFetch extends Thread { J7p),[>I<
[cp+i^f
J/*`7Pd
String sURL; //File URL M/K5#8Arj
long nStartPos; //File Snippet Start Position JaGtsi9%.
long nEndPos; //File Snippet End Position E?0%Z&1h
int nThreadID; //Thread's ID | %Vh`HT
boolean bDownOver = false; //Downing is over XOS[No~
boolean bStop = false; //Stop identical kZ3ThIk%
FileAccessI fileAccessI = null; //File Access interface ,nm*q#R,0
[q #\D
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Dm<A ^u8
{ n6a`;0f[R
this.sURL = sURL; kW&TJP+5*
this.nStartPos = nStart; [IhYh<i
this.nEndPos = nEnd; y h9*z3
nThreadID = id; 9qG6Pb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Jg|XH L)
} emN*l]N
}9fTF:P
dlTt_.
public void run() )hfpwdQ
{ oM`0y@QCf
while(nStartPos < nEndPos && !bStop) L/G6Fjg^
{ ~IN>3\j
c\ lkD-\
]GQG~H^
try{ Q$@I"V&G.
URL url = new URL(sURL); 9zy!Fq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZExlGC
httpConnection.setRequestProperty("User-Agent","NetFox"); TbW38\>.R
String sProperty = "bytes="+nStartPos+"-"; jtc]>]6i
httpConnection.setRequestProperty("RANGE",sProperty); NHZz _a=
Utility.log(sProperty); 9mTJ|sN:e
;MdlwQ$`
:G%61x&=Zc
InputStream input = httpConnection.getInputStream(); QB'aON\S
//logResponseHead(httpConnection); @2 fg~2M1
E09:E
v z '&%(
byte[] b = new byte[1024]; 0.k7oB;f(@
int nRead; W|63Ir67
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7E~;xn;
{ fS78>*K
nStartPos += fileAccessI.write(b,0,nRead); Z}Ft:7
//if(nThreadID == 1) W v+?TEP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A{D];pE`
} Fy-t T]Q9
ckE-",G
2a Q[zK
Utility.log("Thread " + nThreadID + " is over!"); 8c^TT&
bDownOver = true; rCdu0 gYT
//nPos = fileAccessI.write (b,0,nRead); b2&0Hx
} vnZC,J `
catch(Exception e){e.printStackTrace ();} RdRp.pb8
} I(BQ34q
} YGCL2Y
GDiBl*D
p4 ^yVa
//打印回应的头信息 _.Uh)-yR
public void logResponseHead(HttpURLConnection con) %aVq+kC h
{ x-&@wMqkc
for(int i=1;;i++) 'kO!^6=4M
{ lp%pbx43s
String header=con.getHeaderFieldKey(i); ZeaA%y67U
if(header!=null) ~%kkeh\j
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P:MT*ra*,
Utility.log(header+" : "+con.getHeaderField(header)); [%1CRk
else %2V?,zY@
break; K^<BW(s
} +*/Zu`kzX
} z/@slT
9Y_HyOZ*GX
9N3o-=
public void splitterStop() p]2128kqx
{ >V8-i`
bStop = true; )cMh0SGcM1
} jLHkOk5{:
Sk\K4
Ls+2Zbh
} Tqn@P
5f K_Aq{
nazZ*lC
/* Gm^U;u}=f
**FileAccess.java EaY?aAuS:
*//文件访问(定位，写) Zw S F^
package NetFox; U$D65B4=
import java.io.*; N]=q|D
8\A#CQ5b
`Cynj+PCe
public class FileAccessI implements Serializable{ $1L>)S
9w"4K.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1JG'%8}#8
RandomAccessFile oSavedFile; L2i_X@/
long nPos; Pw`8Wj
yZU6xY
6HWE~`ok6
public FileAccessI() throws IOException =ncVnW{
{ i#Bf"W{F
this("",0); `%9 uE(
} ShP^A"Do
u.m[u)HQ
XnMvKPerv'
public FileAccessI(String sName,long nPos) throws IOException Gk&)08
{ FxWSV|Z
oSavedFile = new RandomAccessFile(sName,"rw"); ?_9
this.nPos = nPos; ,CcV/K
oSavedFile.seek(nPos); >7T'OC
} h_3E)jc
fW1CFRHH
! Y~FLA_
public synchronized int write(byte[] b,int nStart,int nLen) :zke %Yx
{ qvKG-|j
int n = -1; w(3G&11N?
try{ K+K#+RBK
oSavedFile.write(b,nStart,nLen); k:#!zK}
n = nLen; [ =9T*Sp
} #:U%mHT(_
catch(IOException e) )e=D(qd
{ Em !/a$
e.printStackTrace (); ' ;FnIZ
} |tMWCA
Hc$O{]sq
vm7z,FfN
return n; @&3EJ1
} lc1(t:"[
qUW! G&R
;LPfXpR
} G3vxjD<DMW
&P}_bx
UapC"XYJ
/* aU "8{
**SiteInfoBean.java li'YDtMKCY
*/ JWhdMU
package NetFox; :tB1D@Cb6
iDz++VNV
Sc1 8dC0
public class SiteInfoBean { gpvYb7Of0
kY|utoAP
%i9E @EV
private String sSiteURL; //Site's URL GxI!{oi2
private String sFilePath; //Saved File's Path U}e!Wjrc
private String sFileName; //Saved File's Name PI:4m%[
private int nSplitter; //Count of Splited Downloading File 17[3/m8a
p6]1w]*R
4I k{
public SiteInfoBean() )@l%
{//nSplitter的缺省值为5 BB!THj69a6
//default value of nSplitter is 5 Fg5kX
this("","","",5); 0$)>D==
} *ebSq)
{JO
7cT~oV !G_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p{Yv3dNl
{ F^t DL:
sSiteURL= sURL; Vvn2 Ep
sFilePath = sPath; 2~1SQ.Q<RY
sFileName = sName; Is)u }
this.nSplitter = nSpiltter; m '|bGV
oWim}Er=
FxtQXu-g
} F|o:W75
j_!F*yul
7{)G_?Q&
public String getSSiteURL() 9Zt`u,;
{ 5j<mbt}
return sSiteURL; :uq\+(9
} ,]ma+(|
tqvN0vY5
D9CaFu
public void setSSiteURL(String value) {W=%U|f
{ t7dt*D_YqK
sSiteURL = value; 4n!aW?%
} .9on@S
z0p*Z&
hk(ZM#Bh
public String getSFilePath() <EB+1GFuI
{ [#<-ZC#T*
return sFilePath; @fZ,.2ar
} |mdVdD~go
( iBl
_"Dv uR
public void setSFilePath(String value) 7a=gH2]&
{ L%*!`TN
sFilePath = value; hYT0l$Ng
} szZr4y<8|1
w;[NH/A^a
@Q ]=\N:
public String getSFileName() c)TPM/>(p
{ LEbB(x;@
return sFileName; UUYSFa%
} {7"Q\
c?f4Q,%|
W7R<%?
public void setSFileName(String value) 25nt14Y0u
{ (Du@ S
sFileName = value; _JzEGpeG
} VuhGx:Xl
?mwt~_s9
=t#llgi~
public int getNSplitter() b(eNmu
{ sQUM~HD\a
return nSplitter; MnsJEvn/
} *)$Uvw E
X:f UI4
p,5i)nEFj
public void setNSplitter(int nCount) |sJ[0z
{ VZp5)-!\
nSplitter = nCount; .KB^3pOpx
} 2@n{yYwy
} [`#CXq'
@wGPqg
SB;&GHq"n
/* YiXk5B0Uh
**Utility.java 7Kr*P<-G
*/ #5Qpu
package NetFox; |PvPAPy)uu
vONasD9At
.wEd"A&j
public class Utility { *<$*"p
ttaM.
aq>kTaz
public Utility() & TCkpS
{ zq3\}9
}kw#7m54
@+&LYy72
} x77*c._3v
!{+,B5 Hc
//线程睡眠 t>L2
public static void sleep(int nSecond) AVsDt2A
{ euK5pA>L
try{ mxvp3t\
Thread.sleep(nSecond); b<tNk]7
} >2Y=*K,:
catch(Exception e) ]{;gw<T
{ $g^@AdE%
e.printStackTrace (); ]}>2D,;
} 6B8VfQ9[
} z 4e7PW|
=Pyj%4Rs
//日志 $f$SNx)),
public static void log(String sMsg) |QF7 uV
{ nQF(vTDN
System.err.println(sMsg); %e8@*~h@
} ]vB$~3||
pE3?"YO
SJlr53
public static void log(int sMsg) rP'me2 B
{ =ke2;}X
System.err.println(sMsg); =1@u
} 2,y|EpG#
} 'NbHa!
G~]Uk*M q
k`cfG\;r
/* ^L,K& Jd
**TestMethod.java =bAx,,D#
*/ ]"pVj6O
package NetFox; }g@v`5
dUD[e,?
WSPI|#Xr%
public class TestMethod { 8$]1M,$r
:^<3>zk
Q8$}@iA[
public TestMethod() Ex.yU{|c
{ ///xx/weblogic60b2_win.exe XMCXQs&
try{ SjK
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !K#qeY}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); a)!o @
SiteFileFetch fileFetch = new SiteFileFetch(bean); p .%]Q*8
fileFetch.start(); #]-SJWf3
} lPe&h]@ >
catch(Exception e){e.printStackTrace ();} JB\UKZXw
p0]=QH
mwO6g~@`
} ^23~ZHu
m%0p\Y-/
I<DL=V
public static void main(String[] args) 7:e{;iG
{ b8H{8{wi|
new TestMethod(); 5G}?fSQ>
} Q1lyj7c#x
} M+oHtX$
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