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)); (!8b$)k
} l'Za"TL:
for(int i=0;i<nEndPos.length-1;i++) jmgkY)rb R
{ "0nsYE
nEndPos = nStartPos[i+1]; AH/^v;-
} GK-P6d
nEndPos[nEndPos.length-1] = nFileLength; hC8WRxEGq
} 8a@k6OZ
} OY(CB(2N
<K&A/Ue
^HR8.9^[1u
//启动子线程 6/3E!8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &+(D< U
for(int i=0;i<nStartPos.length;i++) %{IgY{X
{ #"c'eG0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rZ+4kf6S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #wT6IU1
nStartPos,nEndPos,i); x&J\swN9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KwMt@1Z
fileSplitterFetch.start(); Fhllqh)
} y@$E5sz
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l="X|t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); dHiir&Rd9`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4x-,l1NMR
nEndPos = " + nFileLength); GPGPteC
// fileSplitterFetch[nPos.length-1].start(); H-&27?s^
T<>B5G~%
]!!?gnPd5
//等待子线程结束 4Zu1G#(zP
//int count = 0; @i(9k
//是否结束while循环 u59l)8=
boolean breakWhile = false; {R63n
fnr8{sr.2Z
OESKLjFt
while(!bStop) 3f^jy(
{ *^g]QQ
write_nPos(); Z2g<"M
Utility.sleep(500); {Mb<onW
breakWhile = true; $X-PjQb1Bb
&R.5t/x_
ORP<?SG55u
for(int i=0;i<nStartPos.length;i++) \reVA$M[
{ tboQn~&4
if(!fileSplitterFetch.bDownOver) XRkUv>Yk
{ q,#s m'S
breakWhile = false; IEm~^D#<=
break; (||qFu9a
} "XV@OjrE
} Q_fgpjEh/t
if(breakWhile) M0C)SU5"
break; _2`b$/)-
;u(*&vRqr^
T?[;ej:
//count++; aj|PyX3P:
//if(count>4) S]%,g%6i
// siteStop(); R!/JZ@au<
} 4P)#\$d:
hTO2+F*
Va.TUz4
System.err.println("文件下载结束！"); Md>C!c
} MUZ]*n&0
catch(Exception e){e.printStackTrace ();} >Ho=L)u
} vf>d{F^rv
Bi;a~qE
\$4z@`nY
//获得文件长度 #l&*&R~>
public long getFileSize() oI`Mn3N
{ 1;kMbl]
int nFileLength = -1; OW=3t#"7Kp
try{ g8'8"9:xC
URL url = new URL(siteInfoBean.getSSiteURL()); v,Z]Vqk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (ot56`,k
httpConnection.setRequestProperty("User-Agent","NetFox"); L.;x=w
?&,6Y'"
rq7yNt
int responseCode=httpConnection.getResponseCode(); 3k>#z%//
if(responseCode>=400) qHe H/e%`V
{ '^WR5P<8c
processErrorCode(responseCode); (t5y$bc
return -2; //-2 represent access is error 5QXU"kWH
} zb[kRo&a0W
iNi1+sm
LzLJ6A>;R
String sHeader; Bx}"X?%S
_nzq(m1@
IMdp"
for(int i=1;;i++) _(gkYJ+MK
{ OOIp)=4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,Js_d
//Utility.log(in.readLine()); .WN&]yr,
sHeader=httpConnection.getHeaderFieldKey(i); (JdheCq!x
if(sHeader!=null) y_W?7S
{ (DvGA I
if(sHeader.equals("Content-Length")) NRG~ya >
{ "38<14V
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6ZI7V!k
break; gU&+^e >
} MTl @#M
} ^)Y3V-@t
else &Q"vXs6Gt
break; N GnE
} -*w2<DCn
} ("}Hs[
catch(IOException e){e.printStackTrace ();} ^fd*KM
catch(Exception e){e.printStackTrace ();} u&o4?]6
4%qmwt*p
X1oR
Utility.log(nFileLength); ?RG;q
x~Z7p)D_<
6 mLC{X[
return nFileLength; =&"pG`x
} O{byMV{Ou
t'W6Fmwkx
cC$YD]XdIA
//保存下载信息（文件指针位置） 8R\6hYJ%F
private void write_nPos() x%@M*4:&
{ ~MB)}!S:
try{ $X.F=Kv
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?XyrG1('
output.writeInt(nStartPos.length); %j17QD8
for(int i=0;i<nStartPos.length;i++) g]44|9x(W
{ !U(S?:hvW
// output.writeLong(nPos); pcscNUp
output.writeLong(fileSplitterFetch.nStartPos); hB\BFVUSn/
output.writeLong(fileSplitterFetch.nEndPos); d72 yu3
} <T.R%Jys
output.close(); <)O#Y76s
} q\!"FDOl4
catch(IOException e){e.printStackTrace ();} n@bkZ/G
catch(Exception e){e.printStackTrace ();} 3kGg;z6
} Dvz 6 E
VY~*QF~P
J'=s25OWU
//读取保存的下载信息（文件指针位置） n 78!]O
private void read_nPos() \?e2qu/ C
{ *Z.{1
try{ Fv/{)H<:y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MxGQM>
int nCount = input.readInt(); a>8]+@
nStartPos = new long[nCount]; l1 08.ao
nEndPos = new long[nCount]; r SoT]6/
for(int i=0;i<nStartPos.length;i++) x?0(K=h,
{ p.4Sgeh#
nStartPos = input.readLong(); $ <[r3
nEndPos = input.readLong(); ;*Y+.?>a
} 5gx;Bp^_
input.close(); ;VCFDE{K=
} g0/R\
catch(IOException e){e.printStackTrace ();} O7Jp;
catch(Exception e){e.printStackTrace ();} @c8RlW/A
} AoxORPp'
%O(W;O
*n@rPr-
private void processErrorCode(int nErrorCode) {ByKTx&
{ #|:q"l9
System.err.println("Error Code : " + nErrorCode); #X!seQ7a
} *}(B"FSO
E'8XXV^I?P
9 s2z=^
//停止文件下载 V+0pvgS[
public void siteStop() G6Wa0Z
{ "GqasbX
bStop = true; TK>~)hc}
for(int i=0;i<nStartPos.length;i++) l!j=em@
fileSplitterFetch.splitterStop(); 7I(QTc)*
<Z]j89wzDZ
2"Unk\Y
} jgpF+V-n$
} V*%><r
//负责部分文件的抓取 B=_5gZ4Y
**FileSplitterFetch.java e*D,2>o
*/ \Z~@/OVc
package NetFox; 4uE/!dT
;uZq_^?:9&
Y3)*MqZlF
import java.io.*; V%M@zd?u.
import java.net.*; Iz#jR2:yn
+]H!q W:
9a1R"%Z
public class FileSplitterFetch extends Thread { |w_l~xYV)
ct(euPU
}.=wQ_
String sURL; //File URL ]nxSVKE4p
long nStartPos; //File Snippet Start Position XK0lv8(
long nEndPos; //File Snippet End Position ?LvxEQ-g
int nThreadID; //Thread's ID <1~_nt~(*
boolean bDownOver = false; //Downing is over /W}"/W9
boolean bStop = false; //Stop identical YB{'L +Wbw
FileAccessI fileAccessI = null; //File Access interface \Q?#^<O
PEKXPFN
KlwBoC/{K
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Z y6kA\q
{ Fb{HiU9<!
this.sURL = sURL; O6q5qA
this.nStartPos = nStart; AQ"rk9Z
this.nEndPos = nEnd; gd]k3XN$f
nThreadID = id; <\ ".6=E#W
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d.U"lP/)D
} iNL>TVUM
9I1i(0q
J]NMqiq
public void run() 'J0Ea\,if0
{ z=rSb4"W
while(nStartPos < nEndPos && !bStop) >8`;SEnv
{ mLHl]xs4
%~Wr/TOt+
lj*=bK
try{ 2rf#Bq?7
URL url = new URL(sURL); PP6gU=9[)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sa"!ckh
httpConnection.setRequestProperty("User-Agent","NetFox"); Ob|tA
String sProperty = "bytes="+nStartPos+"-"; xCu\jc)2
httpConnection.setRequestProperty("RANGE",sProperty); $D*Yhv!/
Utility.log(sProperty); fzjtaH?
7zNfq.Ni~
7u%OYt D E
InputStream input = httpConnection.getInputStream(); /)Weg1b
//logResponseHead(httpConnection); 9J}^{AA
ZZeF1y[q
(.$e@k=
byte[] b = new byte[1024]; yW}x
int nRead; `my\59T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /EVXkf0
{ ]6WP;.[
nStartPos += fileAccessI.write(b,0,nRead); BDi+*8
//if(nThreadID == 1) kL -f@CD
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TPi{c_ ]
} ]#FQde4]5
s*e1m%
;l@Ge`&u
Utility.log("Thread " + nThreadID + " is over!"); A(JgAV1{
bDownOver = true; xUB{{8B:L
//nPos = fileAccessI.write (b,0,nRead); \%#luk@:
} Oh7wyQiV
catch(Exception e){e.printStackTrace ();} :-+j,G9t
} gYw=Z_z
} 3e;ux6
$h1pL>^J
V67<Ky>
//打印回应的头信息 pvM`j86 _
public void logResponseHead(HttpURLConnection con) xZMAX}8v
{ )EsFy6K:
for(int i=1;;i++) _E^ !,Wz
{ *Y ?&N2@c
String header=con.getHeaderFieldKey(i); x{VUl
if(header!=null) %cq8%RT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g`H;~ w
Utility.log(header+" : "+con.getHeaderField(header)); RWGAxq`9f
else 6#2E {uy;R
break; vPu{xy
} Vf$q3X
} [ldx_+xa:E
JZ"XrS0?
4m_CPe
public void splitterStop() DV~g
{ K=J">^uW
bStop = true; 3TT?GgQ
} fjy2\J!
\'P79=AU
hh^_Z| 5
} l`EKL2n
n!?u/[@
aN"dk-eK
/* xcXnd"YYE
**FileAccess.java 9P-I)ZqL
*//文件访问(定位，写) kO8oH8Vt
package NetFox; %uy?@e
import java.io.*; fSm|anuKZe
X0]5I0YP
SMHQh.O?5
public class FileAccessI implements Serializable{ -+ Mh('K
~"U^N:I"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 lT F#efcW
RandomAccessFile oSavedFile; XCE<].w
long nPos; o:RO(oA0?
]Cc8[ZC
od]1:8OF
public FileAccessI() throws IOException x^!LA,`j
{ udX!R^8jE
this("",0); NS^+n4
} <ta#2
qoJ<e`h}
k< g
public FileAccessI(String sName,long nPos) throws IOException /cZ-+cu
{ Wg=4`&F^
oSavedFile = new RandomAccessFile(sName,"rw"); <Lfo5:.
this.nPos = nPos; LhtA]z,m
oSavedFile.seek(nPos); U$6(@&P!
} >Te h ?P
NAEAvXj
`&o>7a;
public synchronized int write(byte[] b,int nStart,int nLen) d2<+Pp
{ h[j(@P
int n = -1; Xwk_QFv3
try{ M[5fNK&nD
oSavedFile.write(b,nStart,nLen); E>x,$w<?
n = nLen; &v&e-|r8;
} Q~$hx{foN
catch(IOException e) Gq;!g(
{ tp3 !6I6
e.printStackTrace (); Z oQPvs7_
} G:!'hadw
:LX (9f
[|oOP$u
return n; JCZ5q9b
} pq<2:F:Kl
C4t@;U=x
oa8xuFu(n
} `:;fc
vI+X9C?
'&Tq/;Ml
/* iKe68kx
**SiteInfoBean.java CJ[^Fi?CH
*/ iig@$ i#
package NetFox; kZHIzU
Nmu=p~f}3`
,~qjL|9
public class SiteInfoBean { )W$@phY(I
$|!@$Aj
9i/VvW
private String sSiteURL; //Site's URL {&s.*5
private String sFilePath; //Saved File's Path [5s4Jp$+
private String sFileName; //Saved File's Name C!S(!Z,
private int nSplitter; //Count of Splited Downloading File Tyt1a>!qA
JAP4Vwj%j
s<fzk1LZ
public SiteInfoBean() n*vhCeL
{//nSplitter的缺省值为5 Ox}a\B8
//default value of nSplitter is 5 J={IGA
this("","","",5); l*>,:y
} SOo}}a0
YV/JZc f
RI-)Qx&!f
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?UV!^w@L:0
{ g)Dg=3+>
sSiteURL= sURL; Sv|jR r'
sFilePath = sPath; '7/c7m/$X<
sFileName = sName; eUm,=s
this.nSplitter = nSpiltter; 137:T:
rQ287y{
cXG$zwS\
} jp P'{mc
Wd/m]]W8Q
r@]iy78 j
public String getSSiteURL() .3< sv
{ 3eJ"7sftW
return sSiteURL; kESnlmy@J
} cr<ty"3\
/;a b"b
AWn$od`#s
public void setSSiteURL(String value) 4]%v%64U
{ },(Ln%M
sSiteURL = value; ~xV|<;
} N2Q%/}+,
f%5 s8)
?_Y2'O
public String getSFilePath() Z^SF $+UN
{ !_#2$J*s^D
return sFilePath; /DN!"
} 2C_/T8
;ZowC#j
f<v:Tg.[
public void setSFilePath(String value) J}37 9
{ bO\E)%zp
sFilePath = value; l!YjDm{E
} T9=55tpG9
m*Q*{M_e
3X A8\Mg
public String getSFileName() ^=V b'g3P~
{ Y<EdFzle
return sFileName; 76rRF
} mj9r#v3.
B gB]M3Il
z;d]=PT
public void setSFileName(String value) h,%b>JFo
{ r&?i>.Kz8
sFileName = value; {m2lVzK
} mDJN)CX
Xj("
AEr8^6
public int getNSplitter() !$5.\D
{ FF7
return nSplitter; >@wyiBU
} ?RVY%s;g
6Om)e=gU/
t;e+WZkV
public void setNSplitter(int nCount) T.kQ] h2ZG
{ oD>j26Q
nSplitter = nCount; VLO!hA#
} +9d]([Lx
} Y] "_}
ZAcH`r*
@ATJ|5.gr
/* )`B n"=
**Utility.java [>N`)]fP
*/ "o.g}Pv
package NetFox; _yJAn\
R#0Z
b9gezXAcd
public class Utility { H^N 5yOj/
DEcsFC/SK
vsL)E:0
public Utility() :`w'}h7m
{ lyYi2& %
}E%#g#
/<WK2G
} b ?-VZA:
Q4vl
//线程睡眠 FJl_2
public static void sleep(int nSecond) N 2\lBi
{ 8kwe._&)
try{ Bw;LGEHi|
Thread.sleep(nSecond); ]~H\X":[>
} oPPxjag\
catch(Exception e) |0e7<[
{ {j{H@rHuy
e.printStackTrace (); a.O pxd
} p^uX{!
} R<GnPN:c
jR[3{ Reo
//日志 :s5wFumD
public static void log(String sMsg) tUPdq0%t[
{ $xl>YYEBMH
System.err.println(sMsg); (+^z9p7/!
} C%l+<wpXO
S[zX@3eZV
wmQT$`$b
public static void log(int sMsg) {+V]saYP
{ vL,:Yn@b
System.err.println(sMsg); f,_EPh>
} X/l{E4Ex
} 3r]:k)J
XzBnj7E
,4&?`Q
/* ][IEzeI_LN
**TestMethod.java )* \N[zm
*/ CC<(V{Png
package NetFox; ZWH9E.uj
Jiv%Opo/|
#rkz:ir4
public class TestMethod { 2Vn~o_ga
+=Q/'g
|\W9$V
public TestMethod() +KzbaBK
{ ///xx/weblogic60b2_win.exe `,O#r0m
try{ c6@7>PM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %gb4(~E+N
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1K`7
SiteFileFetch fileFetch = new SiteFileFetch(bean); C=6.~&(
fileFetch.start(); X*^^W_LH.
} $k|:V&6SV
catch(Exception e){e.printStackTrace ();} PS=N]e7k'
4|#@41\ B
jrKRXS
} -xXz}2S4
:47bf<w|Y
&# ?2zbZ
public static void main(String[] args) v,VCbmc
{ TJY [s-
new TestMethod(); 2`?58&
} ip`oL_c
} Q2L>P<87T
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