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)); "+J[7p}`@
} I%31MU9
for(int i=0;i<nEndPos.length-1;i++) 4vRIJ}nQ
{ _D?`'zN
nEndPos = nStartPos[i+1]; Ie8jBf -
} fQOh%i9n5
nEndPos[nEndPos.length-1] = nFileLength; :i:M7}r
} `@|Kx\y4=j
} ?AJE*=b
0^rDf L
*^P$^lm?S
//启动子线程 t.WWahNyY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w"K;e(S
for(int i=0;i<nStartPos.length;i++) 6H}8^'/u
{ Qape DU;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U49 `!~b7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +cnBEv~y
nStartPos,nEndPos,i); RP4P"m(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lGtTZcg
fileSplitterFetch.start(); " )_-L8
} [boB4>.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S^4T#/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); p/!P kKJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (}LLk+
nEndPos = " + nFileLength); 5Mq7l$]h$
// fileSplitterFetch[nPos.length-1].start(); Ykd< }KE>
=HkB>w)h
x4vowF
//等待子线程结束 X6Hd%}*mN
//int count = 0; !c8hER!
//是否结束while循环 T.p:`}Ma
boolean breakWhile = false; j:6VWdgq
\zPcnDB
/{d5$(Y"
while(!bStop) @-QDp`QtI
{ y6S:[Z{~A
write_nPos(); Cn>RUGoUsI
Utility.sleep(500); D#G(&<Q
breakWhile = true; Lcpz(W^
Y^@Nvt$<K
1WW`%
for(int i=0;i<nStartPos.length;i++) Fxr$j\bm
{ 2{o eJ
if(!fileSplitterFetch.bDownOver) sAz]8(Fi0
{ ]#VNZ#("
breakWhile = false; "~&d=f0m
break; 5b^`M
} mlD 1 o
} MKN],l N
if(breakWhile) 9xm'0 '
break; <c&6M
/ !*+9+h
)2jBhT
//count++; wNgS0{}&`
//if(count>4) *N#{~
// siteStop(); ;K9rE3
} oH|<(8efD
zn@yt%PCV
+(|6Wv
System.err.println("文件下载结束！"); JxM[LvVi
} E}WO?xxv74
catch(Exception e){e.printStackTrace ();} $m-rn'Q
} CAl]Kpc
n@Ar%%\
5==}8<$
//获得文件长度 +Ks! 9d*k<
public long getFileSize() ,[{)4J$MV
{ y.:Z:w6$
int nFileLength = -1; b0_Ih6
try{ EecV%E
URL url = new URL(siteInfoBean.getSSiteURL()); C{8d^SCA"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M@/Hd0$
httpConnection.setRequestProperty("User-Agent","NetFox"); KLn.vA.
;{k`nv_6
G*;6cV19
int responseCode=httpConnection.getResponseCode(); N=oWIK<;-
if(responseCode>=400) (yx9ox@rL
{ |NZVm}T
processErrorCode(responseCode); XeT{y]lkd
return -2; //-2 represent access is error &m>sGCZ
} ?$#,h30
nBA0LIb
?{ 0MF
String sHeader; {yPiBu
?Hd/!I&
e5 ?;{H
for(int i=1;;i++) fv",4L
{ NJ;D Qv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dk^Uf84.Gr
//Utility.log(in.readLine()); 2/c^3[ccR
sHeader=httpConnection.getHeaderFieldKey(i); oe8sixZ[
if(sHeader!=null) 2yyJ19Iul
{ ?<iinx
if(sHeader.equals("Content-Length")) Oa'DVfw2J
{ $#/-+>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |9F^"7Q~C
break; w<ol$2&B
} )lo;y~ o
} x]Nk T
else |aT&rpt
break; & bwhD.:=
} ; SS/bS|
} 8"zFTP*;u
catch(IOException e){e.printStackTrace ();} x@ZxV*T^
catch(Exception e){e.printStackTrace ();} O7_u9lz2
R4V~+tnbG&
v?U;o&L(
Utility.log(nFileLength); xSQ:#o=8G
i'$V'x'k
[a<ucJ
return nFileLength; &C.{7ZNt
} 8~=<!(M)m/
'TF5CNX
7( &\)qf=n
//保存下载信息（文件指针位置） !`rR;5&sT
private void write_nPos() \C )S3!h
{ 2k}" 52
try{ P@m_tA%
output = new DataOutputStream(new FileOutputStream(tmpFile)); S<f]Y4A&
output.writeInt(nStartPos.length); MrW#~S|ED
for(int i=0;i<nStartPos.length;i++) $fhb-c3
{ _dgS@n;6
// output.writeLong(nPos); 5ir[}I^z
output.writeLong(fileSplitterFetch.nStartPos); P,|%7'?Y
output.writeLong(fileSplitterFetch.nEndPos); 8+>r!)Q+
} CBqeO@M
output.close(); _%xe:X+ M
} ^4WNP
catch(IOException e){e.printStackTrace ();} {!lC$SlJ
catch(Exception e){e.printStackTrace ();} w$X"E*~>8
} DcO$&)Eb
Y-Zw'
"h-G=vo,kl
//读取保存的下载信息（文件指针位置） <}@*i
private void read_nPos() XA&Vtgu
{ 6`tc]a"#Zb
try{ Rd?8LLz
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8gQg#^,(t
int nCount = input.readInt(); [O"9OW'2!B
nStartPos = new long[nCount]; ScgaWJ
nEndPos = new long[nCount]; gH+s)6
for(int i=0;i<nStartPos.length;i++) JH4hy9i
{ m~[4eH,
nStartPos = input.readLong(); i;u#<y{E
nEndPos = input.readLong(); M x/G^yO9
} :7,j%ELic
input.close(); rjFIK`_w
} XYi-o][Mf
catch(IOException e){e.printStackTrace ();} ,G q?
catch(Exception e){e.printStackTrace ();} >9Yo:b:f
} EpX.{B@B_[
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(;9-8Y&_d
private void processErrorCode(int nErrorCode) Y]xFe>
{ Z%Kkh2-uh
System.err.println("Error Code : " + nErrorCode); 5Iql%~_x
} K}vP0O}
9hJlc
hu]l{TXi
//停止文件下载 TpB4VNi/<
public void siteStop() #2/2Xv
{ 88@" +2
bStop = true; nY>UYSv
for(int i=0;i<nStartPos.length;i++) x1@`\r#0
fileSplitterFetch.splitterStop(); rZij[6]Y^
%`4\ 8H`
gB3Tz(!
} 4Y2!q$}I+
} 8|z@"b l)
//负责部分文件的抓取 #nD]G#>e
**FileSplitterFetch.java #FZoi:'Q
*/ 4x2 ;@Pd
package NetFox; #OQT@uF!
fEWXC|"
j3Sz+kOf,
import java.io.*; Z[,A>tJ
import java.net.*; kBRy(?Mft&
JO3x#1~;_
qg`8f?
public class FileSplitterFetch extends Thread { SHAC(3o/e
Rk8oshS+2
"f Ni3<x]
String sURL; //File URL S [$Os7
long nStartPos; //File Snippet Start Position `y^tCJ2u*
long nEndPos; //File Snippet End Position .|VWYN
int nThreadID; //Thread's ID $:RP tG
boolean bDownOver = false; //Downing is over 3axbWf3[
boolean bStop = false; //Stop identical *_ U=KpZF
FileAccessI fileAccessI = null; //File Access interface ]c+HD*
z#( `H6n:
J)o =0i>*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'yw7|i2
{ Bvai
this.sURL = sURL; ?V{AP&#M$x
this.nStartPos = nStart; $`wo8A|)
this.nEndPos = nEnd; Dcep^8'
nThreadID = id; z6Xn9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,S%DHT
} vNA~EV02
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public void run() ]\.3<^
{ OgOs9=cE{
while(nStartPos < nEndPos && !bStop) k-;A9!^h
{ Y)ig:m]#
~Pm[Ud
KE_GC ;bQ
try{ OsGKlWM/
URL url = new URL(sURL); dfa^5`_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sN8)p%'Lg
httpConnection.setRequestProperty("User-Agent","NetFox"); vJ a?5Jr
String sProperty = "bytes="+nStartPos+"-"; *#| lhf'
httpConnection.setRequestProperty("RANGE",sProperty); [b?[LK}.
Utility.log(sProperty); ?r%kif)
rIhe}1
H6vO}pq)r
InputStream input = httpConnection.getInputStream(); R#\o*Ta
//logResponseHead(httpConnection); k^:+Pp
mC,:.d
2Sha&Z*CE
byte[] b = new byte[1024]; %u@}lG k
int nRead; k0e {c
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m35$4
{ M,R**z
nStartPos += fileAccessI.write(b,0,nRead); RHIGNzSz
//if(nThreadID == 1) BMJsR0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'Cp]Q@]\
} 's>./Pf
EqjaD/6Y`
3m]8>1e1"
Utility.log("Thread " + nThreadID + " is over!"); H7}@56
bDownOver = true; )bkJ['9
//nPos = fileAccessI.write (b,0,nRead); DQ{"6-
} tm#[.
catch(Exception e){e.printStackTrace ();} 7A6:*
} tDQo1,(oY
} z"PU`v
<AN=@`+
C U 8s*
//打印回应的头信息 : 6|nXL
public void logResponseHead(HttpURLConnection con) j +u3VP
{ i9O;D*
for(int i=1;;i++) 7&>==|gt
{ Tz<@k
String header=con.getHeaderFieldKey(i); _]"uq/UWp
if(header!=null) :%2uZ/cG(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?Dn 6
Utility.log(header+" : "+con.getHeaderField(header)); k "Qr
else v*3tqT(%
break; `}o{o
} 8n~ o="
} G{!adBna
%'3Y?d
rWS],q=c
public void splitterStop() }48o{\
{ ~z$+uK
bStop = true; }Lc8tj<
} ZBxV&.9/
xC^|S0B
e{k)]]J
} in>.Tax*
C?-_8OA
V=-hqo(
/* .cCB,re
**FileAccess.java +h?Rb3=S
*//文件访问(定位，写) 8;+dlWp
package NetFox; _WB*ArR
import java.io.*; CWx_9b zk
dxk~
u7G9 eN
public class FileAccessI implements Serializable{ =t!$72g\
ZD`p$:pT
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RuBL_Vi
RandomAccessFile oSavedFile; 7Pp~)Kq=
long nPos; b[;Zl<
Bm:N@wg
'M=c-{f~
public FileAccessI() throws IOException skzTw66W.
{ mJFFst,
this("",0); 1_RN*M+#
} ~z&Ho
9{Xh wi)z
|*te69RX
public FileAccessI(String sName,long nPos) throws IOException 5 cz6\A&
{ 97-=Vb
oSavedFile = new RandomAccessFile(sName,"rw"); 9Lp[y%{GP
this.nPos = nPos; FF'Ul4y
oSavedFile.seek(nPos); Q2jl61d_9
} .~Y% AI
r;'Vy0?AL
1 ,e`,
public synchronized int write(byte[] b,int nStart,int nLen) ^ygh[.e,
{ RAY.]:}jr
int n = -1; rG"QK!R5
try{ iD`>Bt7gD
oSavedFile.write(b,nStart,nLen); ,.-85isco
n = nLen; ^h~oxZJw
} r3mQoTvnv
catch(IOException e) vI1UFD D
{ 5nh:S0M6V
e.printStackTrace (); W;y ,Xs
} qytH<UB
z3|)WS^
j`LvS
return n; V(6GM+
} n}!D)Gx
03^?+[C
e}bY9
} r>.^4Z@
Y&y5^nG
6fcn(&Qk
/* [&H?--I
**SiteInfoBean.java S1G=hgF_L
*/ OYwH$5
package NetFox; ns;nle|m
IP-}J$$1
jSMs<ox
public class SiteInfoBean { [X=J]e^D
Tj_~BT
0$e]?]X6
private String sSiteURL; //Site's URL $kCXp.#k@~
private String sFilePath; //Saved File's Path x39n7+j4
private String sFileName; //Saved File's Name ;VIW/
private int nSplitter; //Count of Splited Downloading File ^Z~'>J
[/Ya4=C@
_?J:Z*z?
public SiteInfoBean() v.pj PBU1
{//nSplitter的缺省值为5 }Pf7YuUZZ
//default value of nSplitter is 5 #M5[TN!
this("","","",5); Tt*n.HA
} o:C],G_
DX)T}V&mP
Z2soy-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &]euL:C
{ \5=fC9*G
sSiteURL= sURL; 'l`T(_zL\%
sFilePath = sPath; +jIE,N
sFileName = sName; q)E J?-
this.nSplitter = nSpiltter; y*fU_Il|!
`Z!NOC
J^]Y`Q`
} $IB>a
+5C*i@v
)Og,VXEB
public String getSSiteURL() KtY_m`DY4R
{ ecl$z6'c
return sSiteURL; IsjD-t
} \/ 8 V|E
Gkq<?q({t
d}e/f)(
public void setSSiteURL(String value) jf'#2-
{ BoMf#l.3B
sSiteURL = value; TRSR5D[
} c7$U0JO
l|onH;g\
{V{*rq<)
public String getSFilePath() K;}h u(*\]
{ |Y42ZOK0
return sFilePath; _8G
} v4V|j<R
8LouCv(>
5 LZ+~!2+
public void setSFilePath(String value) '5vgpmn
{ 4lqowg0
sFilePath = value; sG~5O\,E
} h0)Wy>B=,
qp@:Zqz8
BHW8zY=F
public String getSFileName() XCTee
{ I!;&#LT+b
return sFileName; hiN6]jL|O
} RO1xcCp
9G'Q3? z
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public void setSFileName(String value) "77 j(Vs9
{ `1$7. ydQ
sFileName = value; R;*3";+v|:
} N>$Nw<wV
t6)wR
,Uh7Q-vd
public int getNSplitter() ZxRD+`
{ Kpo{:a
return nSplitter; =os%22*
} e2v[ma-
J}-,!3qxW
,&\uuD&.@
public void setNSplitter(int nCount) Yy"05V.
{ ^|(w)Sy
nSplitter = nCount; liUrw7,
} ?r,lgaw
} u}7#3JfLn
ttwfWfX
IaU
/* n0T'"i[
**Utility.java W]UGo,
*/ 6J|Y+Y$
package NetFox; 4D`T_l
fdD?"z
1o;+.]B
public class Utility { 5$e|@/(0
s C9j73vf
.cQ<F4)!tu
public Utility() [Pu~kiN
{ H?P:;1A]c
q,JMmhWaT
L.[ H
} Z5uetS^
kphv)a4z=
//线程睡眠 ( *(#;|m
public static void sleep(int nSecond) IQS:tL/
{ \V|\u=@H
try{ |8$x
Thread.sleep(nSecond); "b!EtlT9
} NY'sZTM&
catch(Exception e) (o1*7_]e
{ >C`b4xQ
e.printStackTrace (); 1A4!zqT;
} XF{ g~M
} Xz'pZ*Hr$v
1Z +3=$P
//日志 [=Y@Ul
public static void log(String sMsg) 1}C|Javkn
{ /3!KfG
System.err.println(sMsg); $T\z
} @N,EoSb :
$#g1Mx{
d7y`AS@q6
public static void log(int sMsg) Zu\(XN?62
{ X=Q)R1~6v
System.err.println(sMsg); :!M/9D*}0
} #ra~Yb-F
} VfJYYR
coHzbD~#H
)v-sde\
/* +-=w`
**TestMethod.java +zQ a"Ep*
*/ 1f]04TI
package NetFox; x1\,WOrmK
$!L'ZO1_r
]ZGP
public class TestMethod { 92F(Sl
WHQg6r
+ RX{
public TestMethod() TKpka]nJ
{ ///xx/weblogic60b2_win.exe njveZav
try{ F$UvYy4O d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8,pnm
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); hBf0kl
SiteFileFetch fileFetch = new SiteFileFetch(bean); Fu0 dYN
fileFetch.start(); NKD<VMcqw
} :?s~,G_*l
catch(Exception e){e.printStackTrace ();} M-3kF"
QCFLi n+r
`Nn=6[]
} Z5re Fok
%O`e!p
#Jv|zf5Z
public static void main(String[] args) 6fhH)]0
{ 0Zp) DM
new TestMethod(); Y]aVa2!Wb
} t@[&8j2B>
} D.zEE-cGyb
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