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)); J5@_OIc1y
} mEyZ<U9
for(int i=0;i<nEndPos.length-1;i++) tnRq?
{ Z|'tw^0e5
nEndPos = nStartPos[i+1]; e0v&wSi
} BCsW03sQ
nEndPos[nEndPos.length-1] = nFileLength; F'pD_d9]e
} _$i9Tk
} EBK\.[
zVl(?b&CF
u^!-Z)W
//启动子线程 y])xP%q2O
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dYfVox;
for(int i=0;i<nStartPos.length;i++) ]7h&ZF
{ An/)|B4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZLE4XB]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), s49AF
nStartPos,nEndPos,i); ~|l>bf
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lYQcQ*-
fileSplitterFetch.start(); > {fX;l
} mR8&9]g&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,h8)5Mj/J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); o#%2N+w
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2MtaOG2l&q
nEndPos = " + nFileLength); 5x=tOR/h
// fileSplitterFetch[nPos.length-1].start(); sI9~TZ :
rIS \#j
~yB[}BPf
//等待子线程结束 pZjyzH{~
//int count = 0; }KS[(Q
//是否结束while循环 0DS<(
boolean breakWhile = false; UL"JwqD
-2% []
KZ/}Iy>As
while(!bStop) K<Iz5+oD
{ :rk]o*
write_nPos(); q;>'jHh
Utility.sleep(500); Fc 5g~T
breakWhile = true; uysGOyi<u
crZ\:LeJ
;I5HMc_a"
for(int i=0;i<nStartPos.length;i++) Dc #iM0
{ ZVK;m1?'
if(!fileSplitterFetch.bDownOver) Er~5\9,/<]
{ ;v8,r#4
breakWhile = false; BuK82
break; J~n{gT<L
} 'T+3tGCy+
} P(A%z2Ql
if(breakWhile) O3Ks|%1
break; (MJu3t @
urXM}^
?\ho9nyK
//count++; |W\CV0L2
//if(count>4) - Nplx
// siteStop(); }tc,3>/
} pX6OhwkTK
^[^uDE <
=0x[Sa$&,
System.err.println("文件下载结束！"); )0qXZgs
} VPtA %1
catch(Exception e){e.printStackTrace ();} *K-,<hJ#L
} dIIsO{Zqv
"F)7!e
)M'#l<9B
//获得文件长度 }{]{`\
public long getFileSize() w;>]L.n
{ Dve5Ml-
int nFileLength = -1; "QGP]F
try{ fv<($[0
URL url = new URL(siteInfoBean.getSSiteURL()); 9Tjvc!4_b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9dy"Y~c
httpConnection.setRequestProperty("User-Agent","NetFox"); |l7e*$j
U:YT>U1Z
2JtGS-t
int responseCode=httpConnection.getResponseCode(); ed>_=i
if(responseCode>=400) M7!&gFv8
{ (w"zI!
processErrorCode(responseCode); d3^LalAp
return -2; //-2 represent access is error 63-`3R?;
} #Cbn"iYee
Z-]d_Y~m4
+,c;Dff
String sHeader; =2->1<!x6<
>/$Q:92T
n'%*vdHKm
for(int i=1;;i++) |Q.?<T:wt=
{ /$I&D}uR`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _%Mu{Ni&
//Utility.log(in.readLine()); &$vDC M4
sHeader=httpConnection.getHeaderFieldKey(i); }Ct_i'Ow
if(sHeader!=null) p5G O@^i
{ /Hx%gKU
if(sHeader.equals("Content-Length")) /M B0%6m
{ h/eKVRGs"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); AB}Qd\
break; X+bLLW>&
} 6Y\9h)1Jo
} HTkce,dQ
else 6q6&N'We
break; `=%[
} ~''qd\.f$
} X-~Q
catch(IOException e){e.printStackTrace ();} ^'v6 ,*:4
catch(Exception e){e.printStackTrace ();} ^ /:]HG
8>Ervi`
v%86JUlK.
Utility.log(nFileLength); +z("'Cv
P,D >gxl
*w> /vu
return nFileLength; BjOrQAO
} 83;1L:}`
>2>xr"
w&:h^u
//保存下载信息（文件指针位置） E62VuX
private void write_nPos() ,7/un8:%c
{ jwAO{.}T1r
try{ pB?a5jpA
output = new DataOutputStream(new FileOutputStream(tmpFile)); OkA-=M)RI:
output.writeInt(nStartPos.length); +zz9u?2C`
for(int i=0;i<nStartPos.length;i++) >JCSOI
{ OdwSNG
// output.writeLong(nPos); @RbAC*Y]g
output.writeLong(fileSplitterFetch.nStartPos); ~~ )&? \N
output.writeLong(fileSplitterFetch.nEndPos); >,hJ5-9
} XD%?'uUQ_
output.close(); g<}EL[9[J
} P{QRmEE
catch(IOException e){e.printStackTrace ();} nb0<.ICF%R
catch(Exception e){e.printStackTrace ();} 5g/^wKhKG
} a[Txd=b
dA\>z[n=
rYN`u
//读取保存的下载信息（文件指针位置） ot(|t4^
private void read_nPos() LUS7-~:F
{ 90I)"vfW5
try{ '>'h7F=tY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); EkWe6m
int nCount = input.readInt(); Qpf BM
nStartPos = new long[nCount]; 3<fJ5-z|-
nEndPos = new long[nCount]; Ob0=ZW`+&
for(int i=0;i<nStartPos.length;i++) a;/4 ht
{ ~3f#cEP>d}
nStartPos = input.readLong(); [>Q{70 c[
nEndPos = input.readLong(); Q 7B)t;^
} &\Cvrxa
input.close(); EB@!?=0x
} i&.F}bEi
catch(IOException e){e.printStackTrace ();} 4B (*{
catch(Exception e){e.printStackTrace ();} K%Q^2"Eb0
} Mt@K01MI%
iVXR=A\er
WMh'<'wN_
private void processErrorCode(int nErrorCode) 0Xk;X1Xl
{ >+,1@R
System.err.println("Error Code : " + nErrorCode); R&PQ[Xc
} ufEt"P-X.
']+H P9i$
,u~\$Az6
//停止文件下载 1T}|c;fc
public void siteStop() +".&A#wU
{ P]dDTh~e~
bStop = true; uz'beE
for(int i=0;i<nStartPos.length;i++) |W:kzTT-T
fileSplitterFetch.splitterStop(); ua7I K~8l
~}4H=[Zu
S$muV9z2=
} mpr["C"l
} :GL|:
//负责部分文件的抓取 \O7,CxD2
**FileSplitterFetch.java 2(`2f
*/ @J" }~Y
package NetFox; R+!2 j
#Kn7 xn[
bmT J
import java.io.*; mO> [kb"V'
import java.net.*; H~Q UN
IFpmf0;^
:VLuI
public class FileSplitterFetch extends Thread { rD$7;
^D vaT9s
iCv &<C@
String sURL; //File URL ^T^U:Zdq
long nStartPos; //File Snippet Start Position {p6",d."N&
long nEndPos; //File Snippet End Position #/1A:ig
int nThreadID; //Thread's ID TU[f"!z^
boolean bDownOver = false; //Downing is over S@_@hFV jd
boolean bStop = false; //Stop identical WYaDN:kZf
FileAccessI fileAccessI = null; //File Access interface Y>%A*|U%
X4%*&L
O8dDoP\F2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I X\&lV
{ ?>lmLz!e
this.sURL = sURL; f<kL}B+,Og
this.nStartPos = nStart; <;U"D.'
this.nEndPos = nEnd; cpE&Fba}"
nThreadID = id; `5GJ,*{z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 uLL#(bhDr
} Tb{,WUJg2
kN>d5q9b%X
7Jc=`Zm'
public void run() g3x192f
{ RJtSHiM2
while(nStartPos < nEndPos && !bStop) 6;(Slkv
{ \DGm[/P
2M1yw "
!L3Bvb;Q
try{ Y|B/(
URL url = new URL(sURL); o_\b{<^I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6[qRb+ds
httpConnection.setRequestProperty("User-Agent","NetFox"); N?87Bd
String sProperty = "bytes="+nStartPos+"-"; Jw {:1
httpConnection.setRequestProperty("RANGE",sProperty); @ZX{q~g!
Utility.log(sProperty); VK`b'U&l"
sBSBDjk[
Yq5}r?N
InputStream input = httpConnection.getInputStream(); sV[|op
//logResponseHead(httpConnection); &BE[=& |
s|{K?s
"?avb`YU'
byte[] b = new byte[1024]; uVisU%p
int nRead; %FyB\IQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) f#X`e'1
{ p1Lx\
nStartPos += fileAccessI.write(b,0,nRead); EQ=Enw1[
//if(nThreadID == 1) |: nuT$(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :;??!V
} J`"1DlH
fDbs3"H Q
d,D)>Y'h
Utility.log("Thread " + nThreadID + " is over!"); E,C<ox4e
bDownOver = true; eMh:T@SN
//nPos = fileAccessI.write (b,0,nRead); cwpDad[Kx
} 5~.\rcr%
catch(Exception e){e.printStackTrace ();} *]Vx=7D
} ^i:%;oeG
} Ke'bH
C2Y&qX,
Wm3H6o*
//打印回应的头信息 {z.}u5N
public void logResponseHead(HttpURLConnection con) i [j`'.fj
{ &Rn/c}[{
for(int i=1;;i++) I[e7Up
{ MGmtA(
String header=con.getHeaderFieldKey(i); c~C :"g.y
if(header!=null) P, S9gG9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4AF"+L
Utility.log(header+" : "+con.getHeaderField(header)); f-{[ushj
else IndNR:"g
break; EO| kiC
} h+$_:](PC
} %F}`;>C3
SH`"o
<&+l;z
public void splitterStop() Y[x ^59
{ crhck'?0
bStop = true; Zn9w1ev
} I1}{7-_t
%@BQv4oJ
]AHi$Xx
} Tzk8y7$[
X2Lhb{ZHE
}]n&"=Zk-
/* {{<o1{_H
**FileAccess.java !P:hf/l[B
*//文件访问(定位，写) qC3 rHT]
package NetFox; -<s?`Rnk
import java.io.*; T`WFY
pH"LZ7)DI0
f}+G;a9Nj
public class FileAccessI implements Serializable{ :+R||qi
:*oI"U*f
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }wv$ #H[
RandomAccessFile oSavedFile; #lB[]2]N
long nPos; PD/~@OsxU
I&(cdKY z
_nTjCN625
public FileAccessI() throws IOException H%sQVE7m
{ ^lQ-w|7(
this("",0); B2,! 0Re
} b(XhwkGVq
GN~:rdd
H}}t)H
public FileAccessI(String sName,long nPos) throws IOException #Xn#e
{ x?j&Jn_@w
oSavedFile = new RandomAccessFile(sName,"rw"); eg,S(;VEt
this.nPos = nPos; lYZHM,"
oSavedFile.seek(nPos); >ZNL pJQ
} f0^s*V+
c}{e,t
VKs$J)6
public synchronized int write(byte[] b,int nStart,int nLen) UW>~C
{ tSOF7N/<
int n = -1; uZQ)A,#n;
try{ 1-qQp.Wj
oSavedFile.write(b,nStart,nLen); mS);bs
n = nLen; hyTi':
} p jrA:;
catch(IOException e) E|5gKp-wJ
{ ]#*@<T*[
e.printStackTrace (); ~ R*6w($
} TY88PXW
|Y])|`_'G
2cmqtlW"
return n; [&zP$i&
} i"-#1vy=
+ATN2 o
.:lzT"QXI
} D<rjxP
]&9f:5',
Z v~ A9bB
/* q,*IR*B:a
**SiteInfoBean.java O=-|b kO
*/ Mv9s
package NetFox; H?aB8=)
jn+0g:l
"`3H0il;<
public class SiteInfoBean { fB:M'A'
p(U'Ydl~
n&Al~-Q:^
private String sSiteURL; //Site's URL kKjYMYT6
private String sFilePath; //Saved File's Path 3Ys|M%N
private String sFileName; //Saved File's Name pw$I~3OFd
private int nSplitter; //Count of Splited Downloading File 'l;?P
|YlUt~H>
$[>wJXj3R
public SiteInfoBean() vfo[<"
{//nSplitter的缺省值为5 rVN|OLh
//default value of nSplitter is 5 rSZWmns
this("","","",5); 5Pr<%}[S^
} 9Qkww&VEk
ae^xuM?7
N..u<06j/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2`Pk@,:_
{ Lc.7:r
sSiteURL= sURL; ~ h:^Q
sFilePath = sPath; i>rn!?b
sFileName = sName; ^%<v| Y(X
this.nSplitter = nSpiltter; ^L'K?o
qM9GW`CKA
f/=0
} ec3('}X
):\pD]e
[XQNgSy?z
public String getSSiteURL() )kd)v4#
{ =-q)I[4#
return sSiteURL; =djzE`)0
} {#;6$dU;(
cX&c%~
cfj6I
public void setSSiteURL(String value) T&S< 0
{ .oe,#1Qh{
sSiteURL = value; R]r~TJ o
} }U(^QB
]>AW
RSnK`N\9jb
public String getSFilePath() Y0b.utR&
{ <e=0J8V8,i
return sFilePath; wWm#[f],?
} vx ,yz+yP
$]T7Iwk
5(F!*6i>
public void setSFilePath(String value) kPxEGuL'
{ 7v?Ygtv
sFilePath = value; 2GD%=rP2]
} J[B8sa
PCU6E9~t2
*".7O*jjV
public String getSFileName() J]~3{Mi
{ *U]f6Q<X
return sFileName; 'Wi*[
} xp39TiXJ*
0qTa@y
'Gc6ZSLM
public void setSFileName(String value) w5[POo' 5
{ Xr~r`bR=
sFileName = value; o2.! G
} Cr[#D$::`
s9'iHe
/|\`NARI
public int getNSplitter() =]^*-f}J9
{ svQDSif
return nSplitter; "Fke(?X'
} {66vdAu&h<
~k J#IA
?Cu$qE!h)[
public void setNSplitter(int nCount) vw!i)JO8M
{ XkNi'GJf
nSplitter = nCount; z* `81
} ,fNiZ
} O+e8}Tmm
\ 0CGS
`\qU.m0(j
/* ypsCyDQK`
**Utility.java MKH7d/x
*/ '1mygplW
package NetFox; &?9.Y,
@9L%`=]b^
WL7:22nSHa
public class Utility { Jne)?Gt
p*N+B o
p]>bN
public Utility() F6 UOo.L)I
{ !",@,$
CZuxH
YGNX+6Lz
} zxj!ihs<
2AlLcfAW
//线程睡眠 cAL&>T
public static void sleep(int nSecond) m\VJ=
{ 3O]e
try{ 6znm?s@~
Thread.sleep(nSecond); 'LX=yL]I
} [2 Rp.?
catch(Exception e) crmnh4-
{ S^n:O
e.printStackTrace (); wF&\@H
} !.F\v.
} Pq`4Y K
m t*v@'l.
//日志 l"vT@g|
public static void log(String sMsg) foN;Q1?lS
{ 't>Qj7vh0
System.err.println(sMsg); iCc\p2p
} *JDc1$H0
!"1bV [^
rKjQEO$yi
public static void log(int sMsg) ;DGWUK.U[H
{ vWgh?h/ot
System.err.println(sMsg); R `'@$"
} Rc6Rk!^
} 7'<4'BGzl]
WpvH} l r}
X!"y>J
/* :q= XE$%H
**TestMethod.java ,= PDL
*/ Mc\lzq8\ 1
package NetFox; ;or> Sh7
f.u{;W
,%:`Ll t]$
public class TestMethod { A8A+ImwO"
uIba{9tM"P
RJ-CWt [LG
public TestMethod() *}0Q S@FN
{ ///xx/weblogic60b2_win.exe p;'vOb
try{ nU`;MW/^w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >U}~Hv]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q`{.2yV
SiteFileFetch fileFetch = new SiteFileFetch(bean); UjfB+=7I{L
fileFetch.start(); O/5W-u
} mki=.l$O
catch(Exception e){e.printStackTrace ();} Kp99y
9R E;50h
WAQv4&xGM
} BujWql
pu^1s#g8w
-ss2X
public static void main(String[] args) Wd%j;glG
{ h&Sl8$jVp
new TestMethod(); >LNl8X:Cz*
} weDv[b5i
} \Z~m6;
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