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)); jiA5oX^g
} 4Vu'r?
for(int i=0;i<nEndPos.length-1;i++) _W@,@hOH
{ fa!3/X+
nEndPos = nStartPos[i+1]; 85r)>aCMn
} f MY;
nEndPos[nEndPos.length-1] = nFileLength; M^j<J0(O
} F!OOrW]p0
} h1^9tz{
,+ns {ppn
;[{:'^n
//启动子线程 z:Xj_ `p
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N,j>;x3xT
for(int i=0;i<nStartPos.length;i++) !lQ#sL`
{ Z?~gQ $
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `e'G.@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .k# N7[q=
nStartPos,nEndPos,i); -yX.Jv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CRZi;7`*1
fileSplitterFetch.start(); js:C mnI
} do:QH.q8)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GXOFk7>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l `fW{lh
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8A2if9E3
nEndPos = " + nFileLength); 5TXg;v#Z
// fileSplitterFetch[nPos.length-1].start(); KY4d+~2
-W|*fKN`3
u^`eKak"l
//等待子线程结束 Z|2Eb*
//int count = 0; &mh Ln4^
//是否结束while循环 d^KBIz8$5l
boolean breakWhile = false; ]s*5[=uc2
3C277nx
KqN!?anPr
while(!bStop) 5a=nF9/
{ .cw!ls7d
write_nPos(); "DVt3E
Utility.sleep(500); 25xcD1*
breakWhile = true; N=>- Q)
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+?qf`p.{
for(int i=0;i<nStartPos.length;i++) n=f`AmF;
{ iKg75%;t
if(!fileSplitterFetch.bDownOver) |'ZN!2u
{ X3P&"}a
breakWhile = false; IYuyj(/!
break; &g*klt'B
} |.1qy,|!X
} 98BYtxa
if(breakWhile) $GQphXb$
break; .W!tveX8-
uVN.=
>HE,'
//count++; iPMB$SdfO
//if(count>4) ,+~2&>wj
// siteStop(); Q2*/`L}m\
} N1PECLS?
zLh Fbyn(
{J{1`@
System.err.println("文件下载结束！"); pp(H PKs=}
} 2*+3RrJ
catch(Exception e){e.printStackTrace ();} g<fP:/
} Uf# PoQ!y
T}UT7W|
T'hml
//获得文件长度 &kb\,mQ
public long getFileSize() Q`N18I3
{ v#zPH5xo
int nFileLength = -1; d{W}p~UbH
try{ rqF"QU=l
URL url = new URL(siteInfoBean.getSSiteURL()); G]b8]3^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [1NaH
httpConnection.setRequestProperty("User-Agent","NetFox"); i#k-)N _$
H\ 3M
*]5z^> q;7
int responseCode=httpConnection.getResponseCode(); *%3oyWwCd
if(responseCode>=400) x7f:F.
{ !;i*\ a
processErrorCode(responseCode); USprsaj
return -2; //-2 represent access is error FS8S68
} j5zFDh1(
Z)NrhJC
T$u~E1
String sHeader; 7k `_#
dPHw3^J0j
"r@G@pe
for(int i=1;;i++) U M@naU
{ d^tVD`Fm
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *MI)]S
//Utility.log(in.readLine()); vEF=e
sHeader=httpConnection.getHeaderFieldKey(i); PQ,+hq
if(sHeader!=null) 2sUbiDe-
{ )i @1XH"D
if(sHeader.equals("Content-Length")) &RWM<6JP
{ KCD5*xH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Fqo&3+J4
break; d]MGN^%o
} 90p3V\LO
} u)7*Rj^
else Hr6wgYPi
break; H"O$&
} B3Mx,uXT\
} 4Hk6b09
catch(IOException e){e.printStackTrace ();} r ^MiRa
catch(Exception e){e.printStackTrace ();} mk\i}U>`
y<|)'(
h`lmC]X_
Utility.log(nFileLength); lcCJ?!lsSW
*E}Oh
dQai4e>[
return nFileLength; [yC"el6PM
} Ae6("Oid
FRgLlp8x
FOSbe]
//保存下载信息（文件指针位置） @HvScg*Y
private void write_nPos() QNb>rLj52
{ dhW<p5
try{ ge$LIsE8
output = new DataOutputStream(new FileOutputStream(tmpFile)); (`pNXQ0n
output.writeInt(nStartPos.length); Q<yAT(w
for(int i=0;i<nStartPos.length;i++) *2=W5LaK.
{ ywEDy|Wn$~
// output.writeLong(nPos); QF.3c6O@
output.writeLong(fileSplitterFetch.nStartPos); _W|R;Cz]
output.writeLong(fileSplitterFetch.nEndPos); gH'_ymT= 3
} {V0>iN:~S
output.close(); 7 5|pp
} %9X{{_
catch(IOException e){e.printStackTrace ();} s@s/'^`
catch(Exception e){e.printStackTrace ();} HUkerV
} 2h<U
y@`~9$
/VO^5Dnb
//读取保存的下载信息（文件指针位置） wLUF v(&C
private void read_nPos() U{}!y3[wK
{ tOM(U-7Z&
try{ Px#$uU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wyzOcx>M
int nCount = input.readInt(); |!Fk2Je,
nStartPos = new long[nCount]; ]^ #`j
nEndPos = new long[nCount]; zP&q7 t;>
for(int i=0;i<nStartPos.length;i++) ZBJ3VK
{ EE]=f=3
nStartPos = input.readLong(); .'/l'>
nEndPos = input.readLong(); .H2qs{N!
} FCiq?@
input.close(); w" JGO
} zKxvN3!
catch(IOException e){e.printStackTrace ();} .LObOR5J7
catch(Exception e){e.printStackTrace ();} h@@d{{IqT
} 4uUs7T
~ezCu_
qm'b'!gq~
private void processErrorCode(int nErrorCode) B+Z13;}B
{ "yW&<7u1
System.err.println("Error Code : " + nErrorCode); 7)J6/('
} {a@>6)
q^*6C[G B
E/mw* c^
//停止文件下载 i3PKqlp.
public void siteStop() 2tf6GX:
{ E:w:4[neh
bStop = true; g~!$i`_b
for(int i=0;i<nStartPos.length;i++) vCb]%sd-U
fileSplitterFetch.splitterStop(); q}wj}t#
{6O0.}q]&
)o jDRJ&
} [(|v`qMv/g
} rN"Xz
//负责部分文件的抓取 }lP5GT2
**FileSplitterFetch.java /C$ xH@bb
*/ `?9T~,
package NetFox; 8QF2^*RZ7z
*QH[,F`I
M3(k'q7&:
import java.io.*; T4r5s
import java.net.*; '9J*6uXf.
6^E`Sa!s
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public class FileSplitterFetch extends Thread { gvyT-XI
kXwi{P3D$
%LQ/q3?_
String sURL; //File URL .GCR!V
long nStartPos; //File Snippet Start Position ?4G(N=/&
long nEndPos; //File Snippet End Position JMlV@t7y<
int nThreadID; //Thread's ID 1,`H:%z%
boolean bDownOver = false; //Downing is over \A<v=VM|
boolean bStop = false; //Stop identical k)":v3^
FileAccessI fileAccessI = null; //File Access interface +O+<Go@a
V"#Jk!k9k
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException O k7zpq
{ ZJ(rG((!
this.sURL = sURL; %>y;zqZIU
this.nStartPos = nStart; QaQ'OrP
this.nEndPos = nEnd; p<5!02yQ\
nThreadID = id; } 0M{A+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8Kk\*8 <
} OCnFEX"
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public void run() 6Cc7ejt|u
{ VT=K"`EpQ
while(nStartPos < nEndPos && !bStop) mxJXL":|
{ PAZ$_eSK6
= .`jjDJ
Ld(NhB'7
try{ }U[-44r:
URL url = new URL(sURL); 9y^/GwUQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I:$"E% >=
httpConnection.setRequestProperty("User-Agent","NetFox"); {QQl$ys/
String sProperty = "bytes="+nStartPos+"-"; #$'FSy#
httpConnection.setRequestProperty("RANGE",sProperty); fbC~WV#
Utility.log(sProperty); ;6m;M63z
.Yx_:h=u
y3IWfiz>/d
InputStream input = httpConnection.getInputStream(); wsnK3tM7-
//logResponseHead(httpConnection); 8h.V4/?
^%#grX#
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byte[] b = new byte[1024]; }c|UX ZW
int nRead; !/hsJ9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2P9J' L
{ BQjGv?p0s
nStartPos += fileAccessI.write(b,0,nRead); n?E}b$6
//if(nThreadID == 1) Fr5 Xp
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3z[$4L'.
} 2z\;Q8g){r
p=gX!4,9<
S " pI
Utility.log("Thread " + nThreadID + " is over!"); kuKa8c
bDownOver = true; iiNSDc
//nPos = fileAccessI.write (b,0,nRead); `.^ |]|u
} u) *Kws
catch(Exception e){e.printStackTrace ();} WRpyr
} .y):Rh^
} AK2WN#u@Z
n29(!10Px
j*zD0I]
//打印回应的头信息 q;A;H)?g
public void logResponseHead(HttpURLConnection con) CMl~=[foW
{ 'M/([|@
for(int i=1;;i++) Dp!zk}f|
{ {gU&%j
String header=con.getHeaderFieldKey(i); ;dQAV\
if(header!=null) #H5=a6E+q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -]XP2}#d
Utility.log(header+" : "+con.getHeaderField(header)); r:9gf?(&
else y=H@6$2EQ
break; >n$!<
} &mkpJF/
} %Kto.Xq
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.zC*Z&e,.[
public void splitterStop() A';QuWdT
{ {p/YCch,
bStop = true; \:&@;!a
} A3+6#?:;
$sgH'/>
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} /Ox)|)l
g7V_[R(6
<B[G |FY,
/* m,tXE%l
**FileAccess.java 'HaD~pa
*//文件访问(定位，写) 4JO@BV>t
package NetFox; +jV_Wz
import java.io.*; $f-hUOuyo
li/aN
g>0vm2|
public class FileAccessI implements Serializable{ c K<)$*
P))^vUt~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FFzH!=7T?
RandomAccessFile oSavedFile; rC }}r!!
long nPos; (vyz;Ob
`}8&E(<
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public FileAccessI() throws IOException r<yhI>>;<
{ PRr*]$\&Mj
this("",0); fL6e?\Pw
} xPC"c*
p538r[f<
DTY<0Q.
public FileAccessI(String sName,long nPos) throws IOException FvXqggfGv
{ `X8@/wf#
oSavedFile = new RandomAccessFile(sName,"rw"); z<n-Gzwk
this.nPos = nPos; tXq)nfGe{
oSavedFile.seek(nPos); !OE*z $\
} IXq(jhm8bL
CqoG.1jJS
G{lcYP O
public synchronized int write(byte[] b,int nStart,int nLen) N|dD!
{ $p$dKH
int n = -1; @ 4UxRp6+
try{ QLr9dnA
oSavedFile.write(b,nStart,nLen); I}.i@d'O
n = nLen; O\Eqr?%L)
} EzT`,#b
catch(IOException e) Ly #_?\bn
{ AsxD}Nw[Z*
e.printStackTrace (); nk@atK,38^
} n=!uNu7
/QxlGfNZ
r88"#C6E'
return n; p'Bm8=AwD
} ~W{-Q.
Q5n`F5
bToq$%sCg
} 3W&S.$l
$a#H,Xv#
658^"]Rk'/
/* {eHAg<+
**SiteInfoBean.java @x{`\AM|%
*/ dULS^i@@
package NetFox; q|dH~BK
.<&s%{EW
' Q7Y-V
public class SiteInfoBean { 8Y{s;U0n
kiUk4&1
pIO4,VL;W
private String sSiteURL; //Site's URL T>d.#
private String sFilePath; //Saved File's Path 1FERmf? ?d
private String sFileName; //Saved File's Name o0I9M?lP
private int nSplitter; //Count of Splited Downloading File I:=dG[\h2
]<trA$ 0
ls|LCQPx
public SiteInfoBean() 82:Wvp6
{//nSplitter的缺省值为5 x` /)g(
//default value of nSplitter is 5 "/+zMLY
this("","","",5); Qn+:/zA;
} b2)\ MNH
K1q+~4>\|
T*>`,}J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <bUe/m
{ ,+1m`9}
sSiteURL= sURL; X.#oEmA,P
sFilePath = sPath; ;L"!I3dM)
sFileName = sName; }31ZX
this.nSplitter = nSpiltter; &m'kI
zG9|K
?IhB-fd>@
} @,OT/egF4:
$g\&5sstE
QMp rv*i
public String getSSiteURL() ]r/^9XaqtA
{ d7Ro}>lp
return sSiteURL; wij,N(,H
} _D;@v?n6!O
mG2'Y)Sz
E4oz|2!m
public void setSSiteURL(String value) m&Yi!7@(
{ C/@LZ OEL
sSiteURL = value; I.jZ wW!r
} 8l+H"M&|
k*Nr!Z!}
#I0pYA2m
public String getSFilePath() jAhP> t:
{ B6M+mx"G
return sFilePath; SoQR#(73HK
} \k@$~}xD,
*75YGD
Gt-UJ-RR y
public void setSFilePath(String value) B!S167Op
{ )u} Q:`9
sFilePath = value; {=Q7m`1
} _GA$6#]
([E]_Q
A o/vp-e
public String getSFileName() Z S|WnMH
{ M"Y0jQ(
return sFileName; "lVqU
} l|"6yB |
[M+tB"_
,T5u'";
public void setSFileName(String value) I0Ia6w9
{ ?ny=
sFileName = value; uh3)0.nR
} xBM>u,0.F
`'4)q}bB
= [@)R!3H
public int getNSplitter() :nJgwp()@
{ ?vtX"Fdz
return nSplitter; &xd.Qi2
} i!H!;z#
Va<eusl
/bVZ::A&_
public void setNSplitter(int nCount) YZwaD b
{ J7$_VP
nSplitter = nCount; n! h7
} S-Fo
} 4YROB912
a\5FAkI
{E_{JB~`
/* 2KJ1V+g@a6
**Utility.java p~jlx~1-]
*/ &X>7n~@0
package NetFox; 5f7zk
kuMKX`_
1Y/$,Oa5
public class Utility { Im72Vt:p-
ot%.M*h-
_^S]gmE
public Utility() C"pB"^0
{ 7}o/:
HIc a nk
OM83S|1s
} uGH?N
LF<wt2?*
//线程睡眠 -_A$DM!^=w
public static void sleep(int nSecond) \Ad7 Gi~
{ t%VDRZo7
try{ ]`o!1(GA
Thread.sleep(nSecond); Ud%s^A-qS
} =\kMXB
catch(Exception e) {3\R|tZh,`
{ wxQ>ifi9Z
e.printStackTrace (); %j,iAUE<
} ^rAa"p9
} +OaUP*\Dd
/pH(WHT+/H
//日志 U>qHn'M
public static void log(String sMsg) ODw`E9
{ h1D?=M\9
System.err.println(sMsg); |L3X_Me
} |`rJJFA
j]4,<ppWSH
vDj;>VE2b
public static void log(int sMsg) m.Lij!0
{ B;#J"6w
System.err.println(sMsg); k[|~NLB8
} ixfdO\nU
} Y}G_Z#-!
IVvtX}
b'p4wE>
/* n.6T OF
**TestMethod.java Xz{~3ih
*/ 7:=k`yS,
package NetFox; R[[ ,q:4
m]Y;c_DO:
M!m?#xz'c
public class TestMethod { t;qP']2
U]6&b
&m^@9E)S/
public TestMethod() KM,|} .@:
{ ///xx/weblogic60b2_win.exe A$/\1282
try{ :%rS =f
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); XVVD 0^ Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]1`g^Z@ 0
SiteFileFetch fileFetch = new SiteFileFetch(bean); WY
fileFetch.start(); [j,txe?n
} #&.]" d
catch(Exception e){e.printStackTrace ();} &p(0K4:
wVl+]zB
GC@+V|u
} =6 r:A<F!n
7N8H)X
J1ON,&[J
public static void main(String[] args) BzJ;%ywS
{ A&5:ATQ/|
new TestMethod(); L1m{]>{-
} cDEJk?3+
} %8.J=B
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