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)); @"*8nV#
} x(e=@/qp
for(int i=0;i<nEndPos.length-1;i++) D`;Q?fC
{ B!vI^W
nEndPos = nStartPos[i+1]; _)q,:g~fu
} d7xd"
nEndPos[nEndPos.length-1] = nFileLength; 1D /{Y
} +U(m b
} O -a`A.
Z/ "jLfP
*@'\4OO
//启动子线程 MQR@(>TZy
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \Rc7$bS2H
for(int i=0;i<nStartPos.length;i++) VP4W~;UV|\
{ hWGCYkuW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,UFr??ZKm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^L&hwXAO:
nStartPos,nEndPos,i); Y4PB&pZ$O2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iJg3`1@j
fileSplitterFetch.start(); :Mss"L820
} Q3SwW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q]%c 6{w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8$fiq}a
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qMAH~P0u
nEndPos = " + nFileLength); ;c5Q"
// fileSplitterFetch[nPos.length-1].start(); *KP 60T
9aw- n*<
pKrol]cth8
//等待子线程结束 O!!Ne'I
//int count = 0; *g$egipfF
//是否结束while循环 X<4h"W6
boolean breakWhile = false; gi;#?gps
~eH+*U|\|M
\lVX~r4
while(!bStop) I!y[7^R
{ }.<%46_Z-
write_nPos(); ]KMOLe6(
Utility.sleep(500); hSmu"a,S
breakWhile = true; _"8\k7S*
56Q9RU(M
pq`Bg`c
for(int i=0;i<nStartPos.length;i++) JFx=X=C
{ NGHzifaE
if(!fileSplitterFetch.bDownOver) Z:|2PQ4
{ A*ImruV
breakWhile = false; Z6<vLc
break; {0fQ"))"
} gk+$CyjJ
} fDmGgD?
if(breakWhile) %(`4wo},
break; pb~&gliW
c43"o
6aG/=fq
//count++; _DChNX
//if(count>4) iP1u u
// siteStop(); Ws[[Me,=
} ]p(jL7
<tZPS`c'_
1MdVWFKXV
System.err.println("文件下载结束！"); \*#9Ry^f
} UOrfwK
catch(Exception e){e.printStackTrace ();} jP6;~[rl
} .^^YS$%%7
;|v6^2H"
]*+ozAG4
//获得文件长度 rIz"_r
public long getFileSize() zmI?p4,
{ XfFZ;ul
int nFileLength = -1; `, ?T;JRc
try{ !*wK4UcX"
URL url = new URL(siteInfoBean.getSSiteURL()); b'Gn)1NE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6KmF 9
httpConnection.setRequestProperty("User-Agent","NetFox"); kW&{0xkGR
<o5+*X
q2}<n'o+
int responseCode=httpConnection.getResponseCode(); Lxm1.TOJ
if(responseCode>=400) K#g)t/SZ
{ Z3=DM=V;v
processErrorCode(responseCode); EJYfk?(B
return -2; //-2 represent access is error xq',pzN
} -`6O(he
<Tr_,Ya{9
7~[1%`
String sHeader; 4 Yq|Z
zO`54^
f<ABs4w
for(int i=1;;i++) STp}?Cb
{ VIL #q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ml8'=KN_
//Utility.log(in.readLine()); ANh5-8y
sHeader=httpConnection.getHeaderFieldKey(i); >\b=bT@iM
if(sHeader!=null) 2s,wC!',
{ >S5:zz\
if(sHeader.equals("Content-Length")) ,L&Ka|N0
{ 8Pklw^k
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); RRy3N )HR
break; Fs7/3
} >G<AyS&z*
} zH8l-0I+$
else JZ&]"12]fR
break; V ^=o@I
} fL4F ~@`9l
} =8 d`qS"
catch(IOException e){e.printStackTrace ();} ):C4"2l3
catch(Exception e){e.printStackTrace ();} {{M?+]p,^
+0;n t
.H+`]qLkL
Utility.log(nFileLength); 6/9 A'!4C
aX6.XHWbDf
NL))!Pi
return nFileLength; &;7\/m*W1
} C(C4R+U
z%t>z9hU
5I5~GH
//保存下载信息（文件指针位置） ]SpUD
private void write_nPos() kEWC
{ xmZ]mu,,$
try{ D!TL~3d 1
output = new DataOutputStream(new FileOutputStream(tmpFile)); Gk2\B]{
output.writeInt(nStartPos.length); 0Ph,E
for(int i=0;i<nStartPos.length;i++) 4O[T:9mn0
{ &O(z|-&| x
// output.writeLong(nPos); b#|M-DmT
output.writeLong(fileSplitterFetch.nStartPos); 0o[p<<c*
output.writeLong(fileSplitterFetch.nEndPos); z7F~;IB*u
} {U4BPKof
output.close(); |{]\n/M
} o9~Z! &p
catch(IOException e){e.printStackTrace ();} KcP86H52I
catch(Exception e){e.printStackTrace ();} S'vi +_
} DGdSu6s$
-8Z%5W`
^r73(8{)
//读取保存的下载信息（文件指针位置） vWI9ocl`W
private void read_nPos() 9}t2OJS*h"
{ LOi5 ^Um|
try{ z=vfP%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "y/GK1C
int nCount = input.readInt(); f;#hcRSH
nStartPos = new long[nCount]; UO8#8
nEndPos = new long[nCount]; Z2`(UbG}
for(int i=0;i<nStartPos.length;i++) e4Ol:V
{ u*Eb4
nStartPos = input.readLong(); /r Zj=
nEndPos = input.readLong(); "YHqls}c
} 31k.{dnm
input.close(); C/ow{MxA
} 9f;\fe
catch(IOException e){e.printStackTrace ();} |"DQ^)3Pi
catch(Exception e){e.printStackTrace ();} Q u2W
} QNzI
=dUeQ?>t=
Ix !O&_6s
private void processErrorCode(int nErrorCode) i;`rzsRb
{ em<(wJ-Y
System.err.println("Error Code : " + nErrorCode); D_D<N(O
} X'e@(I!0
1Ah
)#Ea~>v
//停止文件下载 5YMjvhr?W
public void siteStop() ` :Am#"j]}
{ Dms6"x2
bStop = true; W1M<6T.{7
for(int i=0;i<nStartPos.length;i++) =:mD)oX*
fileSplitterFetch.splitterStop(); &%L1n?>Q}
|i7|QLUT
\kZxys!4
} cF3V{b|bU
} $`x4|a8-
//负责部分文件的抓取 &V$_u#<
**FileSplitterFetch.java (}vi"mCeW
*/ )U e9:e
package NetFox; >y"V%
l~Hs]*jm
5`*S'W}\>
import java.io.*; K+TRt"W8&s
import java.net.*; dGMBgj
I0sd%'Ht?
Hq"i0Xm
public class FileSplitterFetch extends Thread { ,95Nj h
=K~<& l8
BZ<Q.:)
String sURL; //File URL 4]u53`
long nStartPos; //File Snippet Start Position X0+$pJ60
long nEndPos; //File Snippet End Position w0x,~
int nThreadID; //Thread's ID ?V"X=B2
boolean bDownOver = false; //Downing is over DzYi> E:*
boolean bStop = false; //Stop identical 5X4; (Qj
FileAccessI fileAccessI = null; //File Access interface ".onev^(
6pM[.:TM
R8Nr3M9 )
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _dVzvk`_R
{ ?d0I*bs)7
this.sURL = sURL; :% )va
this.nStartPos = nStart; xrxORtJ<
this.nEndPos = nEnd; b;`gxXeL
nThreadID = id; lhva|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bEyZRG
} &z8@ rk|
,]\L\V
NGtSC_~d
public void run() $(K[W}
{ puA~}6C
while(nStartPos < nEndPos && !bStop) \"{+J
{ k?3NF:Yy7
d4t%/Uh
}&Ngh4/
try{ }p$>V,u
URL url = new URL(sURL); qasbK:}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !#` .Mv Z
httpConnection.setRequestProperty("User-Agent","NetFox"); py VTA1
String sProperty = "bytes="+nStartPos+"-"; b/HhGA0
httpConnection.setRequestProperty("RANGE",sProperty); D/^yAfI
Utility.log(sProperty); ZH;VEX
W2P(!q>r]
cm@q{(r
InputStream input = httpConnection.getInputStream(); ?%dsY\
//logResponseHead(httpConnection); ET;YAa*
Xd@ -
<0g.<n,
byte[] b = new byte[1024]; k#NIY4%.
int nRead; @{3$H^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !f[LFQD
{ =v]\{.
nStartPos += fileAccessI.write(b,0,nRead); eG*<=.E
//if(nThreadID == 1) Y|FF ;[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q}p&<k
} #kjN!S*=
@?lmho?
dc.9:u*w
Utility.log("Thread " + nThreadID + " is over!"); C?m2R(RF
bDownOver = true; w$8Su:g=
//nPos = fileAccessI.write (b,0,nRead); m1H_kJ
} b6Pi:!4
catch(Exception e){e.printStackTrace ();} wO9|_.Z{
} ej,j1iB
} k/o"E
EKo!vieG
_b|mSo,{Y
//打印回应的头信息 j>Wb$p6S
public void logResponseHead(HttpURLConnection con) cu*8,*FU
{ 6RV42r^pf
for(int i=1;;i++) IA I!a1e!
{ ~(bY-6z
String header=con.getHeaderFieldKey(i); S^(OjS
if(header!=null) w#mnab@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $X<O\Kna
Utility.log(header+" : "+con.getHeaderField(header)); l*~O;do
else ?!TFoD2'
break; {~q"Y]?
} `u6CuH5
} MIma:N_c
UtPFkase
nX%b@cOXj
public void splitterStop() YbAa@Sq@
{ ;]c@%LX
bStop = true; Wd"<u2
} l7#5.%A
IlN: NS
#$W02L8
} 0T,uH
/2z, ?,jL
OBY^J1St
/* )+ifVv50
**FileAccess.java j'r"_*%
*//文件访问(定位，写) 4P(muOS
package NetFox; X.}i9a 6
import java.io.*; /c2| *"@X
JC6?*R
`%S 35x9
public class FileAccessI implements Serializable{ 'kBg3E$y
A1>fNilC9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0PEg `Wq
RandomAccessFile oSavedFile; |pLx,#n
long nPos; (~S=DFsP
lRA=IRQ]
s1 mKz0q
public FileAccessI() throws IOException qFQO1"mu
{ bmCp:6
this("",0); m8[XA!,
} xf2|9Tqt
FgwIOpqE*
$[f-{B{>*
public FileAccessI(String sName,long nPos) throws IOException 7slpj8
{ Cp"a,%b6u
oSavedFile = new RandomAccessFile(sName,"rw"); 7)Cn 4{B6
this.nPos = nPos; )+GwYt
oSavedFile.seek(nPos); %lsRj)n
} 7:/gO~gI
<|-da&7
T)c<tIr6
public synchronized int write(byte[] b,int nStart,int nLen) ,J;Cb}
{ W*2d!/;7>
int n = -1; #hMS?F|
try{ 6LRvl6ik
oSavedFile.write(b,nStart,nLen); SG$V%z"e
n = nLen; m3T=x =
} _c!$K#Yl{
catch(IOException e) trx y3k;
{ ?Vre"6U
e.printStackTrace (); [D%(Y ~2
} ^(F@#zN}
76oJCNY
s5s'[<
return n; -v %n@8p
} px${ "K<
%eOO8^N
gOy;6\/
} l+nT$IPF
wn-1fz<d
*Jwx,wF}4
/* ldFR%v>9
**SiteInfoBean.java zgNzdO/B
*/ =;Q:z^S
package NetFox; 0SjB&J
)JrG`CvdU
q-hREO
public class SiteInfoBean { \s?8}k
jK-b#h.gL
P,J+'.@
private String sSiteURL; //Site's URL Y_zMj`HE
private String sFilePath; //Saved File's Path 8bJj3vr
private String sFileName; //Saved File's Name %* k`z#b
private int nSplitter; //Count of Splited Downloading File H\fsyxM7
+'|nsIx,
zC,c9b
public SiteInfoBean() X$2f)3
{//nSplitter的缺省值为5 zJ6""38Pr
//default value of nSplitter is 5 OwCbv j0#
this("","","",5); oGRd ;hsF
} 6gs0Vm
6Ki!j<
9-+N;g!q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) uf^HDrr<L
{ `r'$l<(4WV
sSiteURL= sURL; =`ZRPA!aY
sFilePath = sPath; hmkm^2
sFileName = sName; ,njlKkFw^Z
this.nSplitter = nSpiltter; 9OYyR
boq=@Qh
72CHyl`|l
} ]ZnASlc)
P$x9Z3d_
Jmuyd\?,b
public String getSSiteURL() h% eGtd$n
{ I&U.5wf
return sSiteURL; @<.ei)cqb
} L} "bp
u69UUkG
{/j gB"9
public void setSSiteURL(String value) R<B5<!+
{ P;`Awp?
sSiteURL = value; jF-:e;-
} 9}wI@
43 vF(<r&f
..kFn!5(g
public String getSFilePath() +MZI\>
{ D;&\)
return sFilePath; G^sx/H76J
} Xs{PAS0
_7z]zy@PC5
{O:{F?
public void setSFilePath(String value) aGd wuD
{ j1;<3)%0
sFilePath = value; DRpFEWsm
} ;F|#m,2Q-
riL|B3
KL6B!B{;
public String getSFileName() 2!6E~<~HC
{ d>?C?F
return sFileName; 9Fy'L#%
} le' Kp V
OwT_W)$
]>Ym
public void setSFileName(String value) Q*Y-@lZ
{ 'ieTt_1.G
sFileName = value; wfv\xHG
} jEE!H/
8_E(.]U
twu,yC!
public int getNSplitter() XG*> yra`
{ qyxd9Lk1
return nSplitter; Gy[anDE&
} Oi'y0S~g
R7"7 Rx
Ab]tLz|Z
public void setNSplitter(int nCount) 2i0;b|-=
{ !u'xdV+bf
nSplitter = nCount; "F}dZ
} z#Fel/L`O
} q 'd]
]ag{sU@#
Q5}XD
/* s1E 0atT
**Utility.java tfe]=_U
*/ 0%Le*C'yk
package NetFox; /* qx5$~
H[nco#
z{|0W!nHJ
public class Utility { =tbfBK+
P6Y+ u
/7])]vZ_
public Utility() 7~FHn'xt
{ >DUTmJxv
n 7i5A:
0TaI"/ai
} ;<q2
!d<R=L
//线程睡眠 =%<, ^2o
public static void sleep(int nSecond) eM{u>n+`F0
{ IA<>+NS
try{ vQ*RrHG?c
Thread.sleep(nSecond); `kJ)E;v;3
} Pjk2tf0j`
catch(Exception e) ]E-3/r$_cO
{ 1I`F?MT
e.printStackTrace (); _?:jZ1wZ
} Arg/ge.y
} @!=Ds'MJC
&ocuZ-5`
//日志 6`7tTn?n
public static void log(String sMsg) ">.tPn
{ ;-8.~Sm
System.err.println(sMsg); dVYY:1PS
} WKiP0~
QmjE\TcK/
;&n iZKoe
public static void log(int sMsg) y%ij)vQY
{ f*<Vq:N=\
System.err.println(sMsg); F{;#\Ob
} (BPO*'
} ~CT]&({
>G8I X^*sG
&:5*^1oP
/* >t)Pcf|s
**TestMethod.java C 2nmSXV
*/ FJDC^@Ne
package NetFox; bJetqF6n
X5YOxMq
t$(#$Z,RS
public class TestMethod { CDM6o!ur3
_\KFMe=PV
Dc@O Mr
public TestMethod() 5"@>>"3U
{ ///xx/weblogic60b2_win.exe {Y@shf;
try{ ~9 .=t'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cFw-JM<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l>K+4
SiteFileFetch fileFetch = new SiteFileFetch(bean); cN0 *<
fileFetch.start(); 1R3,Z8j'
} !DzeJWM|
catch(Exception e){e.printStackTrace ();} #<< el;n
BW7AjtxQ&
{iX#
} ". tW5O>
|dLr #+'az
wYf\!]}'
public static void main(String[] args) . 2$J-<O
{ 5PO_qr=Hx
new TestMethod(); JyZuj>` 6
} 7JGc9K+Av
} l<w7 \a6
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