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)); ijr*_=
} [4kx59J3b
for(int i=0;i<nEndPos.length-1;i++) :|<D(YA
{ lcJ`OLG
nEndPos = nStartPos[i+1]; ll1?I8}5|
} ?8-e@/E#x
nEndPos[nEndPos.length-1] = nFileLength; +hY/4Tx<
} WaWT 5|A
} dmP*2
P{(m:`N
ex'd^y
//启动子线程 #Q 2$v;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >G' NI?$
for(int i=0;i<nStartPos.length;i++) `C=!8q
{ 3, ,Z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $7TYix8=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), uP|AP
nStartPos,nEndPos,i); Vt n$*ML
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?-#w [J'6
fileSplitterFetch.start(); +SPC@E_v
} @WhcY*R2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), akm)X0!-}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xVfJ]Y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /Ia=/Jj7N
nEndPos = " + nFileLength); {aGQ[MH\9
// fileSplitterFetch[nPos.length-1].start(); 1uB}Oe2~
Zdh4CNEeFP
zZDG5_$n
//等待子线程结束 IZJV6clM
//int count = 0; eX?o4>
//是否结束while循环 kt[#@M!}
boolean breakWhile = false; sN-5vYfC*
p]!,BoZL
T]Tz<w W(
while(!bStop) SnQ$
{ d#ld*\|
write_nPos(); 8k_,Hni
Utility.sleep(500); SwC,=S
breakWhile = true; *sAoYx
xhUQ.(S`r6
8Y5* 1E*
for(int i=0;i<nStartPos.length;i++) rRT9)wDa
{ b\=0[kBQw
if(!fileSplitterFetch.bDownOver) ,"h$!k"$g
{ `*}#Bks!
breakWhile = false; )KXLL;]
break; +]uy
} !G\1$"T$
} 8"oS1W
if(breakWhile) w$Dp m.0(
break; Vy}:Q[
w/YKWv{_S
4yRT!k}o
//count++; Ba`]Sm=
//if(count>4) bXJ,L$q
// siteStop(); C!qW:H
} xBB:b\
WpTC,~-
%*|XN*iXC
System.err.println("文件下载结束！"); yc%AkhX*
} 14oD^`-t
catch(Exception e){e.printStackTrace ();} fD,#z&
} 3XL0Pm
QR4v6*VpD
Yo7ctwzdH;
//获得文件长度 @q^WD_k
public long getFileSize() #\`6ZHW
{ gkBat(Uc
int nFileLength = -1; H[-zQ#I9
try{ O,^,G<`
URL url = new URL(siteInfoBean.getSSiteURL()); >IoOCQQ*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !m_'<=)B4~
httpConnection.setRequestProperty("User-Agent","NetFox"); zw5EaY
j{p0yuZ)<
).v;~yE
int responseCode=httpConnection.getResponseCode(); OEB_LI'
if(responseCode>=400) {\]SvoJnJ
{ mT!~;]RrF
processErrorCode(responseCode); F>^k<E?,C
return -2; //-2 represent access is error w?Q@"^IL
} IDLA-Vxo
c (\-7*En
OmU.9PDg-
String sHeader; ;yHA.}
s?0r\cc|:
QQC0uta`
for(int i=1;;i++) .Z/"L@
{ Nkv2?o>l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A\4Gq
//Utility.log(in.readLine()); )}paQmy#
sHeader=httpConnection.getHeaderFieldKey(i); >Pv%E
if(sHeader!=null) dZnq 96<:|
{ N.&)22<m9
if(sHeader.equals("Content-Length")) uX.Aq@j
{ {Ziq~{W_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X^aujK^@
break; QF%@MK0zC
} &mY<e4
} _II;$_N
else :Ur%.0
break; (%I`EAR
} Lo;T\CN
} =faV,o&{`
catch(IOException e){e.printStackTrace ();} 7Kh+m@q.
catch(Exception e){e.printStackTrace ();} tM@TT@.t~
+ FLzK(
N4HnW0
Utility.log(nFileLength); q=96Ci_a
r/{0YFa
t$Qav>D
return nFileLength; i ;X'1TN(y
} -sc@SoS
hKX-]+6"
D}3E1`)W
//保存下载信息（文件指针位置） }r,k*I'K
private void write_nPos() QV?\?9(
{ F~* 5`o
try{ N:&^ql4
output = new DataOutputStream(new FileOutputStream(tmpFile)); *a$z!Ma3h
output.writeInt(nStartPos.length); V2.MZ9
for(int i=0;i<nStartPos.length;i++) u_:" u
{ 0Q>Yoa 11
// output.writeLong(nPos); hV=)T^Q
output.writeLong(fileSplitterFetch.nStartPos); :k(aH Ua
output.writeLong(fileSplitterFetch.nEndPos); ["@K~my~D*
} lHP[WO
output.close(); 8.9S91]=
} 1h)I&T"kZ
catch(IOException e){e.printStackTrace ();} Gia_B6*Y[
catch(Exception e){e.printStackTrace ();} oq0G@
} 0eUsvzz15
B}*xrPj
N2~DxVJ5cT
//读取保存的下载信息（文件指针位置） $e<3z6
private void read_nPos() kA#>Xu/
{ a&y%|Gs^f
try{ Bd\p!f<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2abWIw4
int nCount = input.readInt(); d_]MqH>R\
nStartPos = new long[nCount]; JsiJ=zo<
nEndPos = new long[nCount]; l&T;G9z
for(int i=0;i<nStartPos.length;i++) n{UB^-}5
{ 8+GlM+>4
nStartPos = input.readLong(); Pb[wysy
nEndPos = input.readLong(); ,T1t`
} eqjl$QWPJS
input.close(); r!#a.
} L4Kkbt<x
catch(IOException e){e.printStackTrace ();} eOLS
catch(Exception e){e.printStackTrace ();} nk6xavQji
} r[~Km5
NCl={O9<j
.Olq_wuH
private void processErrorCode(int nErrorCode) >eJk)qM
{ b`%/*
System.err.println("Error Code : " + nErrorCode); f+gyJ#R`
} *+Q,b^N
TQnMPELh"
'VO^H68
//停止文件下载 PW.W.<CL
public void siteStop() Fdvex$r&
{ <4(rY9
bStop = true; 30F&FTW
for(int i=0;i<nStartPos.length;i++) V-I_SvWv\
fileSplitterFetch.splitterStop(); w"A'uFXLc
5N ' QG<jE
T_I"Tsv
} SDJAk&Z}R
} >Wy@J]Y#
//负责部分文件的抓取 IURi90Ir
**FileSplitterFetch.java =DF7l<&km
*/ [n66ZY#U]
package NetFox; +KD~/}C%-
u^V`Ucd"R
vp-)$f&
import java.io.*; Pk*EnA)
import java.net.*; 5z#>>|1>#
-*tP_=-Dg
\.Q"fd?a_D
public class FileSplitterFetch extends Thread { a"hlPJlG
WO_cT26Y
&a-:ZA@
String sURL; //File URL 6)DYQ^4y
long nStartPos; //File Snippet Start Position ZmYp!B_~
long nEndPos; //File Snippet End Position 9h~>7VeZ)
int nThreadID; //Thread's ID b/ur!2yr
boolean bDownOver = false; //Downing is over P3@[x
boolean bStop = false; //Stop identical OGh bHa
FileAccessI fileAccessI = null; //File Access interface v>0xHQD*<M
TX8,+s+
@\[&_DZ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gxL5%:@
{ HiVF<tN
this.sURL = sURL; K3 "co1]u
this.nStartPos = nStart; n_?<q{GW
this.nEndPos = nEnd; A^o
nThreadID = id; :^?ZVi59j
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2rD`]neA
} f*kT7PJG
30[?XVI&
H VG'v>s@
public void run() KqaeRs.u
{ aoMQ_@0
while(nStartPos < nEndPos && !bStop) RI cA)I.
{ zneK)C8&q3
P1H`NOC
1>l{c
try{ oREZ^pE@
URL url = new URL(sURL); nG{jx_{`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J&Le*R'
httpConnection.setRequestProperty("User-Agent","NetFox"); voV=}.(p
String sProperty = "bytes="+nStartPos+"-"; ;>|:I(l;
httpConnection.setRequestProperty("RANGE",sProperty); ILTd*f
Utility.log(sProperty); I)DLnnQQ
j3z&0sc2(0
o_os;
InputStream input = httpConnection.getInputStream(); &|Z:8]'P
//logResponseHead(httpConnection); T4qbyui{
ugucq},[
6}{2W<
byte[] b = new byte[1024]; Jp_{PR:&
int nRead; F]SexP4:A
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E}\^GNT
{ QT\S>}
nStartPos += fileAccessI.write(b,0,nRead); Q_LPLmM
//if(nThreadID == 1) IN`05Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fm:/}7s
} y&9v0&o
+<@7x16
"D8xHHb
Utility.log("Thread " + nThreadID + " is over!"); uXu'I
bDownOver = true; q^Oq:l$s
//nPos = fileAccessI.write (b,0,nRead); N$?mula
} 7P:0XML}
catch(Exception e){e.printStackTrace ();} Yq<D(F#qx
} :]e:-JbT4z
} OFCkQEG=y>
QQ1+uY
A3yVT8
//打印回应的头信息 A$fd6+{
public void logResponseHead(HttpURLConnection con) 6$@Pk<w
{ rb&^ei9B
for(int i=1;;i++) 1OE^pxfi>
{ &RpQ2*4n
String header=con.getHeaderFieldKey(i); A CJmy2
if(header!=null) BJ~Q\Si6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~F>oNbJIv
Utility.log(header+" : "+con.getHeaderField(header)); u.8vXc
else )d0&iE`@
break; k/!Vv#8
} w0tlF:Eg
} c3i|q@ k
e+4p__TmZ
^/mQo`[G
public void splitterStop() LQNu]2
{ m7^a4
bStop = true; g|e^}voRM
} `=b*g24z[N
NZ9`8&93
J'^BxN&
} SM![ yC
F)5QpDmqb
1H-R-NNJ:
/* RYS]b[-xZz
**FileAccess.java JB''Ujyi
*//文件访问(定位，写) 9v0.]
package NetFox; =5I1[p;
import java.io.*; 6DR@$fpt
@l>\vs<
(al7/EhY
public class FileAccessI implements Serializable{ fZxZ):7i
Nki18ud#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 iN+p>3w^l
RandomAccessFile oSavedFile; mcS/-DaN?
long nPos; U|-4*l9Ed
KW^s~j
VlXIM,
public FileAccessI() throws IOException Z]uN9c
{ $//18+T
this("",0); N, ;'oL+
} ^7F!>!9Ca
fcD$km
u%VO'}Gz
public FileAccessI(String sName,long nPos) throws IOException BAdHGwomh
{ k[y{&f,
oSavedFile = new RandomAccessFile(sName,"rw"); 6~;fj+S
this.nPos = nPos; a5L#c=
oSavedFile.seek(nPos); 'rp(k\pY
} -md2Z0^ Kc
dGP*bMCT
L.l%EcW=,
public synchronized int write(byte[] b,int nStart,int nLen) _BtppQIWv
{ +7N6]pK|"
int n = -1; ZCbxL.fFz
try{ m$pXe<
oSavedFile.write(b,nStart,nLen); @\u)k
n = nLen; %jKR\f G
} @Eqc&v!O
catch(IOException e) g%1!YvS3v
{ 91mXvQ:u
e.printStackTrace (); #x)G2T'?
} V{ra,a*
}_@cqx:n^
6:ZqS~-
return n; #}:VZ2Z
} "g>uNtt~
( F0.lDZ
sjWhtd[fgG
} 2"yzrwZ:
D#W{:_f
n_.2B$JD
/* 8[(c'rl|)|
**SiteInfoBean.java u2JkPh&!rq
*/ X[h=UlF
package NetFox; h8u(lIRHQ
<uu1e@P
-NiFO
public class SiteInfoBean { A{y3yH`#h
3vQ?vS|2
hY-;Wfg
private String sSiteURL; //Site's URL |KplbU0iC
private String sFilePath; //Saved File's Path TjgX' j
private String sFileName; //Saved File's Name 4kxy7]W
private int nSplitter; //Count of Splited Downloading File :NA cad
<kPU*P,
`^wF]R
public SiteInfoBean() j05ahquI
{//nSplitter的缺省值为5 ZMg%/C
//default value of nSplitter is 5 i,4
this("","","",5); *=~ 9?
} 2=(=Wjk.
[q9TTJ@2
A6q,"BS^d
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) f.V0uBDN
{ qaG%PH}a
sSiteURL= sURL; P,_GTs3/G
sFilePath = sPath; *)L%pH>`
sFileName = sName; D@>P%k$$s>
this.nSplitter = nSpiltter; &tLg}7?iB
>pG]#Z g
u;h9Ra1
} =Ky1v$<
\P&'4y~PL
EG7ki0
public String getSSiteURL() y 9/27yWB
{ $hg W>e
return sSiteURL; ^p|@{4f]
} P,xayy
h"#^0$f
0Q]x[;!k
public void setSSiteURL(String value) - Kj$A@~x
{ ,UH`l./3DX
sSiteURL = value; o=w&&B
} PKwHq<vAsB
PX\}lTJ
pc^(@eD
public String getSFilePath() Rj^bZ%t
{ ,yAvLY5P
return sFilePath; Ga N4In[d
} rQj.W6w=
lv&<kYWY
]1abz:
public void setSFilePath(String value) 31Zl"-<#-
{ +%UXI$v
sFilePath = value; VP0wa>50!
} ? Yy[8_(tN
7EQ |p
(+CB)nV0IA
public String getSFileName() D GOc!
{ 7KuTC%7
return sFileName; '#u|RsZ
} DWm$:M4z
y9Yh%M(
[AE]0cO@
public void setSFileName(String value) L7q%u.nB1
{ 6>Lr
sFileName = value; c}g^wLa
} q,0o:nI
mBQ6qmK
]*[S#Jk
public int getNSplitter() 3$(1LN
{ E-.M+[
return nSplitter; 'S@h._q
} QmbD%kW`3
b==<7[8
7!Ym~M=
public void setNSplitter(int nCount) o LuGW5wzj
{ *1Nz VV
nSplitter = nCount; 5c3)p^]g
} C1r]kF
} k2k/v[60
*oZBv4Vh
_d %H;<_
/* ,F6i5128{
**Utility.java l')?w]|
*/ kX+y2v(2++
package NetFox; wKXKc\r
KosAc'/ M
vT\`0di~
public class Utility { ;w}ZI<ou
K}&|lCsb
\AoM'+
public Utility() iNd8M V
{ }yx'U 3
0K@s_C=n#
P]j{JL/g&
} M:Xswwq
x_2 [+Ol
//线程睡眠 pRPz1J$58
public static void sleep(int nSecond) y5BNHweaRb
{ 8iqx*8}
try{ o_bj@X
Thread.sleep(nSecond); /DQoM@X
} 9_KUUA
catch(Exception e) 1;]cYIq
{ MftX~+
e.printStackTrace (); F>96]71 2
} qZ6P(5X
} w[~$.FM/
v&xk?F?WU,
//日志 X<#Q~"
public static void log(String sMsg) z<sf}6q
{ |XLx6E2F
System.err.println(sMsg); ~y$B#.l
} %RdCSQ9~
-9.S?N'T>;
tm#T8iF
public static void log(int sMsg) NVcL9"ht*@
{ %fJ*Ql4M
System.err.println(sMsg); .Rd@,3
} Beiz*2-}a
} xzz[!yJjG
azS"*#r6}
0p*(<8D}
/* dfO@Yo-?*'
**TestMethod.java `:}GE@]
*/ |A8xy#
package NetFox; 4F??9o8}
)l\BZndf
H}dsd=yO
public class TestMethod { do+HPnfDzU
tceQn ^|<
5m=3{lBi
public TestMethod() *&% kkbA
{ ///xx/weblogic60b2_win.exe 8ooj)
try{ 9"I/jd0B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b_W0tiyv%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); vp[~%~1(
SiteFileFetch fileFetch = new SiteFileFetch(bean); esLPJx
fileFetch.start(); kzbgy)PK3
} q/XZb@rt
catch(Exception e){e.printStackTrace ();} Pi40w+/
>]&LbUW+
{h7*a=
} 600-e;p
BN|+2D+S
#T99p+O
public static void main(String[] args) Hhx<k{B@7
{ ,fT5I6l
new TestMethod(); S^c5
} RI')iz?
} vaxNF%^~yN
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