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)); GiB3.%R`
} a3 wUB
for(int i=0;i<nEndPos.length-1;i++) aT"q}UTK
{ [i.2lt#]
nEndPos = nStartPos[i+1]; N\DEY]
} GAbX.9[V
nEndPos[nEndPos.length-1] = nFileLength; v')Fq[H
} t#oY|G3O}
} $k*E^~qT
!l@IG C
YY]JjMkU
//启动子线程 {) 4D1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :{%6<j
for(int i=0;i<nStartPos.length;i++) O'U0Y8HN
{ 2t\a/QE)E
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3> -/sii
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |)i-c`x
nStartPos,nEndPos,i); Y1txI
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gm9e-QIHK
fileSplitterFetch.start(); \?h +
} /<s'@!W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ROr$Sz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;JA2n\iP,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w``t"v4
nEndPos = " + nFileLength); yInW?3
// fileSplitterFetch[nPos.length-1].start(); BqK|4-Pf
k}l5v)m
e{.2*>pH
//等待子线程结束 "m):"
//int count = 0; c[?S}u|['
//是否结束while循环 nK1XJp
boolean breakWhile = false; l%.3hId-
=&xamA)
d~uK/R-KD
while(!bStop) ZT95g
{ U/Z!c\r
write_nPos(); jE2k\\<a
Utility.sleep(500); |HI=ykfI
breakWhile = true; {w}PV5<
q .nsGbl
[3;J,P=&
for(int i=0;i<nStartPos.length;i++) zm\=4^X
{ w<&Nn`V
if(!fileSplitterFetch.bDownOver) ]K?z|&N|HK
{ 4vPQuk!
breakWhile = false; a*6x^R;)
break; beEdH>
} bSU9sg\
} 2X;,s`)
if(breakWhile) /!oi`8D
break; ${ad[hs
J %jfuj
AnG/A!G
//count++; AF ZHS\
//if(count>4) [Nr6qxWg
// siteStop(); V' "p a
} o;M"C[
8},!t\j#]
8b!&TP~m1
System.err.println("文件下载结束！"); !0`44Gbq
} 9s6, &'
catch(Exception e){e.printStackTrace ();} jY$Bns&.w
} 2!cP[Ck
i;y<gm"
[zn`vT
//获得文件长度 Vd4x!Vk
public long getFileSize() ;" '`P[
{ k4'rDJfB
int nFileLength = -1; ZGSb&!Ke
try{ R0_%M
URL url = new URL(siteInfoBean.getSSiteURL()); f8L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [{ K$sd
httpConnection.setRequestProperty("User-Agent","NetFox"); F=Z|Ji#
s{x2RDAt
qxG@Zd
int responseCode=httpConnection.getResponseCode(); m[!t7e
if(responseCode>=400) Ex^7`-2,B
{ #JYv1F
processErrorCode(responseCode); ^O6PZm5J}
return -2; //-2 represent access is error $d{{><
} ;VeC(^-eh6
!h}x,=`z/
]}i_NqW)
String sHeader; V9I5/~0c
@sav8]
3%|LMX]M5_
for(int i=1;;i++) jl{>>TW{x
{ k+'Rh'>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~A}"s-Kq5
//Utility.log(in.readLine()); .d^8w97
sHeader=httpConnection.getHeaderFieldKey(i); &sh %]o8
if(sHeader!=null) }ARWR.7Cc
{ #n]js7
if(sHeader.equals("Content-Length")) 'D-eFJ5
{ xV}E3Yj2#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !3v!BJ#+,&
break; }?$d~]t)
} y+_GL=J
} K;,n?Q w
else +IK~a9t
break; 7]@vPr;:
} gnlGL[r|
} A/lxXy}D
catch(IOException e){e.printStackTrace ();} [53rSr
catch(Exception e){e.printStackTrace ();} F +D2 xN@
1mwb&j24n3
@E{c P%fv
Utility.log(nFileLength); ea3AcT6
H\W60|z9
^j[>.D
return nFileLength; *$Aneq0f
} xv]P-q0
':R)i.TS
iSUn}%YFz!
//保存下载信息（文件指针位置） #b4`Wcrj
private void write_nPos() .wtb7U;7
{ #yFDC@gH1
try{ id\0yRBt
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8OqG{jmG
output.writeInt(nStartPos.length); n AQB
for(int i=0;i<nStartPos.length;i++) <@.f#
{ U`ey7
// output.writeLong(nPos); ,oT?-PC$z
output.writeLong(fileSplitterFetch.nStartPos); t~)w921>
output.writeLong(fileSplitterFetch.nEndPos); wr~# rfH
} MIub^ $<C
output.close(); .!\y<9
} 1RY}mq
catch(IOException e){e.printStackTrace ();} Os?G_ziIB
catch(Exception e){e.printStackTrace ();} m4<8v
} UtIwrR[
QzT)PtX
;-~Wfh+
//读取保存的下载信息（文件指针位置） ~QJD.'z
private void read_nPos() ?y>xC|kt
{ Se9I1~mX
try{ :aV(i.LW
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O _yJR
int nCount = input.readInt(); 4Smno%jq
nStartPos = new long[nCount]; y>'^<xk
nEndPos = new long[nCount]; OthQ)&pqX
for(int i=0;i<nStartPos.length;i++) cR[)[9}
{ W#$ pt>h)
nStartPos = input.readLong(); Sir7TQ4B
nEndPos = input.readLong(); .M!6${N);
} gG1%.q
input.close(); >M<rr!|
} Q1mz~r
catch(IOException e){e.printStackTrace ();} d!{,[8&
catch(Exception e){e.printStackTrace ();} &[`p qX
} Vl5}m
B=%cXW,
:J`:Q3@
private void processErrorCode(int nErrorCode) ^:5;H=.
{ %a<N[H3NV@
System.err.println("Error Code : " + nErrorCode); SouPk/-B80
} @aN<nd`q)
n7i;^=9mM
.e!dEF)D
//停止文件下载 3+u11'0=t
public void siteStop() x$QOOE]
{ ,'v]U@WK
bStop = true; (Gf1#,/3~
for(int i=0;i<nStartPos.length;i++) :/c=."z.
fileSplitterFetch.splitterStop(); PaP47>(
\|BtgT*$b
B_i@D?bTD
} '*MNRduE6
} ]hpocr
//负责部分文件的抓取 3kx/Q#
**FileSplitterFetch.java ),v[.9!}:
*/ /Z';#G,z
package NetFox; wQgW9546
j#$ R.
vQ2kL`@
import java.io.*; q+.DZ @
import java.net.*; rY4{,4V
&s->,-,
Pni
public class FileSplitterFetch extends Thread { t%Vc1H2}
$`(}ygmP
;Xk-hhR
String sURL; //File URL b?jRA^
long nStartPos; //File Snippet Start Position %Ui&SZ\
long nEndPos; //File Snippet End Position 'e_^s+l)a
int nThreadID; //Thread's ID L,*2tJcC<
boolean bDownOver = false; //Downing is over tPIT+1.]z
boolean bStop = false; //Stop identical xgn@1.}G
FileAccessI fileAccessI = null; //File Access interface ~J^Gzl
NVU@m+m~
7pH(_-TF
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |&`NB|
{ }]$%aMxy T
this.sURL = sURL; fNPHc_?Ybj
this.nStartPos = nStart; kngkG|du
this.nEndPos = nEnd; }26?bd@e`
nThreadID = id; lCLz!k2di
fileAccessI = new FileAccessI(sName,nStartPos);//定位 v!27q*;8H
} 7tP?([o%F
9G_bM(q'^2
i 2hP4<;h
public void run() J3KY?,g3O_
{ mRZC98$ @r
while(nStartPos < nEndPos && !bStop) Y*/:IYr`
{ 3?iRf6;n
.0kltnB
? acm5dN
try{ .Qm"iOyM
URL url = new URL(sURL); U+>!DtOYK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }&BE*U8_
httpConnection.setRequestProperty("User-Agent","NetFox"); ^\Tde*48
String sProperty = "bytes="+nStartPos+"-"; _eb:"(m
httpConnection.setRequestProperty("RANGE",sProperty); q4'szDYO2
Utility.log(sProperty); CE]0OY
S1sNVW
p \A^kX^5
InputStream input = httpConnection.getInputStream(); o%XAw
//logResponseHead(httpConnection); B{$4s8XU
,*$L_itL
A;7p
byte[] b = new byte[1024]; 7nM]E_
int nRead; xpCzx=n3.m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +EjH9;gx
{ =cI -<0QSn
nStartPos += fileAccessI.write(b,0,nRead); <@6K(
//if(nThreadID == 1) 3>YG
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SxMmy
} *yKw@@d+p
A:PQIcR;V
Wd#r-&!6j
Utility.log("Thread " + nThreadID + " is over!"); /tR@J8pV
bDownOver = true; G8dC5+h
//nPos = fileAccessI.write (b,0,nRead); ,e$]jC<sv2
} FDBj<uXfM|
catch(Exception e){e.printStackTrace ();} ts%XjCN[
} 7s@%LS
} WP[h@#7<
4>eY/~odq]
1Z%^U ?
//打印回应的头信息 B64L>7\>`
public void logResponseHead(HttpURLConnection con) ,<R/jHZP9
{ 0NrUB
for(int i=1;;i++) @yiAi:v@
{ H~IR:WOw
String header=con.getHeaderFieldKey(i); `>KB8SY:qK
if(header!=null) JAJo^}}{b
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "#1KO1@G
Utility.log(header+" : "+con.getHeaderField(header)); V'?bZcRr~
else *`$Y!uzG:\
break; q-gp;Fm
} H8.Aq\2S
} ,l/~epx4v)
hG51jVYtw
Lc4\i
public void splitterStop() ?#~3%$>
{ lZ]x #v
bStop = true; tQ0iie1Ys
} ?.Mw
ERD( qL.J
f$#--*
} gS{hfDpk,h
'-C%?*ku
zURxXo/\V
/* cV^r_E\m
**FileAccess.java 6[ }~m\cY
*//文件访问(定位，写) r9nH6 Md\
package NetFox; ,dn6z#pb+
import java.io.*; !qGER.
4@ EY+p
L3}n(KAJj
public class FileAccessI implements Serializable{ 6r
);EW(7KeL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 XG_h\NIL
RandomAccessFile oSavedFile; ^w]N#%k\H
long nPos; yKupPp);
pFE&`T@ <
r\nKJdh;ka
public FileAccessI() throws IOException dJyf.VJ
{ X*f#S:kiNU
this("",0); C>l{_J)n
} ' cM2]<
Nl"Xl?y}
;MRK*sfw{
public FileAccessI(String sName,long nPos) throws IOException I ACpUB
{ V9aGo#
oSavedFile = new RandomAccessFile(sName,"rw"); iA*^`NMaT
this.nPos = nPos; ^na8d's:
oSavedFile.seek(nPos); ]?KTw8j}
} lO^Ly27
y[QQopy4:
NQBa+N
public synchronized int write(byte[] b,int nStart,int nLen) W)F<<B,
{ f};lH[B3y
int n = -1; > mI1wV[
try{ Pn?Ujjv
oSavedFile.write(b,nStart,nLen); "rxhS; R1>
n = nLen; /mS|Byx
} R`M>w MLH
catch(IOException e) &n6'r^[D
{ mEK0ID\
e.printStackTrace (); ( X(61[Lu
} \tv^],^`
tc-pVw:TV
t<8vgdD
return n; Oz8"s4Y7
} Z8vMVo
Ug :3)q[O
K|n%8hRy
} jhRg47A
R#"LP7\
<4lR
/* B=<>OYH
**SiteInfoBean.java 9, A(|g
*/ =*paa
package NetFox; WY>r9+A?W
hM_0/o-
qDSZ:36
public class SiteInfoBean { hY*ylzr83
.\Z/j
kHWW\?O
private String sSiteURL; //Site's URL 2EO WbN}M
private String sFilePath; //Saved File's Path O_v8R7 {
private String sFileName; //Saved File's Name +/"Ws'5E
private int nSplitter; //Count of Splited Downloading File IBP3
y4N8B:j%
]|H`?L
public SiteInfoBean() K)ZW1d;
{//nSplitter的缺省值为5 h?Y->!'
//default value of nSplitter is 5 11"- taWj
this("","","",5); /#<R
} V(gmC%6%l*
qu8!fFQjYL
R_DstpsT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1w`]2
{ /z=xEnU#
sSiteURL= sURL; 2wCSjAWWh(
sFilePath = sPath; 2OA0rH"v
sFileName = sName; cWp5' e]A
this.nSplitter = nSpiltter; W;Pdbf"
3VI[*b
S['rfD>9
} B|\JGnNQ
kjj4%0"
d#tqa`@~
public String getSSiteURL() i`nmA-Zj[
{ YLXLaC[
return sSiteURL; Gt4/ax:A@
} |_6V+/?"?`
kT-dQ32
|2Krxi3*
public void setSSiteURL(String value) %>];F~z
{ 0 _n Pq
sSiteURL = value; (7X|W<xT
} RJpRsr
zh.^> `
y 4 wV]1
public String getSFilePath() "V=IG{.
{ I ~U1vtgp
return sFilePath; )7aUDsu>4
} *\-$.w)k
&gxWdG}qx]
B|f =hlY
public void setSFilePath(String value) mBwM=LAZ
{ _YK66cS3E/
sFilePath = value; w$)NW57[|
} C{*' p+f
{+3 `{34e
h]+UK14m
public String getSFileName() u# TNW.
{ '9ki~jtf=
return sFileName; a<NZC
} W>E/LBpE4
\4`:~c
5wE+p<-KX
public void setSFileName(String value) JI3x^[(Z
{ ron-v"!
sFileName = value; %#jW
} x]Pp|rHj
,<CFjtelO
6*aU^#Hz6
public int getNSplitter() =,Zkg(M
{ hl/) 1sOIR
return nSplitter; FHK{cE
} X7~^D[X
hEh` cBO
%&5PZmnW
public void setNSplitter(int nCount) /g]NC?
{ K\trT!I
nSplitter = nCount; 3 0.&Lzz
} c:[8ng 2v
} e0$.|+
5r` x\
6uTFgSqZ
/* mB5Sm|{
**Utility.java ufi:aE=}
*/ L%`MoTpKq
package NetFox; FKH_o
<r1/& RW,
KU=+ 1,Jf
public class Utility { )z_5I (?&
Be~'@
*'n L[]
public Utility() 8yC/:_ML
{ /8? u2 q
*%ta5a
LTTMxiq[*
} iBt<EM]U/
]~@uStHn
//线程睡眠 7PW7&]-WQ
public static void sleep(int nSecond) Pr_DMu
{ .Cu0G1
try{ u*m|o8
Thread.sleep(nSecond); d6XdN
} j0~dJ#
catch(Exception e) )tv~N7
{ =.]{OT
e.printStackTrace (); <dKHZ4
} aT~=<rEDy
} w+Y_TJ%
dAr=X4LE
//日志 { V$}qa{P
public static void log(String sMsg) .Q!pQ"5
{ s>I~%+V.?:
System.err.println(sMsg); J(Fk@{!F.*
} FvXpqlp
n#S?fsQN
:I2spBx
public static void log(int sMsg) )E*-
{ Kw =RqF
System.err.println(sMsg); FM"[:&>
} 1l s8h
} ~hb;kc3
8 +mW
&e3pmHp'
/* T`2a)
**TestMethod.java v@,`(\Ca'
*/ 7?ILmYBw
package NetFox; 0C4Os p
AbL(F#{
}p>l,HD
public class TestMethod { s[;1?+EI
"9IR|
X2mZ~RB(p
public TestMethod() pD]2.O
{ ///xx/weblogic60b2_win.exe )S9}uOG#
try{ `4,]Mr1b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); zgl$ n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ge]Z5E(1
SiteFileFetch fileFetch = new SiteFileFetch(bean); tP89gN^PA|
fileFetch.start(); }\QXPU{UVd
} zHD8\*
catch(Exception e){e.printStackTrace ();} u`"Y!*[ -
N8)]d
v)aV(Oa
} r-_-/O"l
eB9F35[
v.53fx
public static void main(String[] args) ? CU;
{ R(s[JH(&
new TestMethod(); W/.n R[!
} I2gSgv%
} J4Ca0Ag
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