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)); Cr|v3Y#h'
} 2)]C'
for(int i=0;i<nEndPos.length-1;i++) -]"=b\Q
{ *f|9A/*B3
nEndPos = nStartPos[i+1]; cn#JO^8
} x \B!0"~
nEndPos[nEndPos.length-1] = nFileLength; `"QUA G
} hWpn~q
} bUbM}
%\#s@8=2u
&RP!9{F<
//启动子线程 *%_:[>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +cv7]
for(int i=0;i<nStartPos.length;i++) e:}8|e~T
{ Icf 4OAx
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -C.x;@!k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), d&'z0]mOe
nStartPos,nEndPos,i); +F q`I2l|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yyZH1A
fileSplitterFetch.start(); g/,fjM_
} 49n.Gc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wh[+cH"M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ao)hb4ex
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3nv7Uz
nEndPos = " + nFileLength); mMmzi4HL
// fileSplitterFetch[nPos.length-1].start(); [o8a(oC
8>a/x,
Vt{C80n&N
//等待子线程结束 R_J=x
//int count = 0; Jhu<^pjs
//是否结束while循环 @!6eRp>Z
boolean breakWhile = false; >kOca
BX$t |t;!m
{V%ZOdg9
while(!bStop) eCdx(4(\a
{ Zzr+p.
write_nPos(); ie+&@u
Utility.sleep(500); hH:7
breakWhile = true; c.jq?Q k
\V`O-wcJ]S
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for(int i=0;i<nStartPos.length;i++) cAC2Xq
{ Rt~Aud[
if(!fileSplitterFetch.bDownOver) -H~g+i*J
{ k9UmTvX
breakWhile = false; pW O-YZ#+
break; P$_Y:XI !
} VA.jt}YGE
} */xI#G,O+
if(breakWhile) 5P{dey!
break; \@nmM&7C!4
B5Rmz&
pVn6>\xa
//count++; I=&5mg=m
//if(count>4) ,R0@`t1 p
// siteStop(); 5)V]qV$
} gVCkj!{
q]:+0~cz
nk9hQRP? 8
System.err.println("文件下载结束！"); Y{Kpopst
} DCX4!,ZF
catch(Exception e){e.printStackTrace ();} =O1CxsKt6
} Mo &Ia6^
//KTEAYyy#
:Oo
//获得文件长度 mn\e(WoX
public long getFileSize() qhVDC
{ isHa4 D0
int nFileLength = -1; UV)[a%/SB&
try{ ^te9f%>$l
URL url = new URL(siteInfoBean.getSSiteURL()); l3n* b6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }aXc,;Ps
httpConnection.setRequestProperty("User-Agent","NetFox"); KXcG;b[7n
N-jFA8n
gqNd@tYI
int responseCode=httpConnection.getResponseCode(); hF+YZU]rT
if(responseCode>=400) E5 H6&XU
{ ;3Fgy8T
processErrorCode(responseCode); $y\'j5nk3
return -2; //-2 represent access is error 00?^!';
} 8gJ"7,}-'
e`4OlM]
X1:|
String sHeader; Cst\_j
A)040n
s!Y>\3rMW
for(int i=1;;i++) {#uX
{ r$;DA<<|<c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 56u'XMB?
//Utility.log(in.readLine()); $ePAsJ
sHeader=httpConnection.getHeaderFieldKey(i); z1f~:AdL
if(sHeader!=null) 9NaC7D$,
{ //Ioh (N
if(sHeader.equals("Content-Length")) ^w^cYM,
{ eL^,-3JA(]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J[L$8y:
break; ex $d~
} ,V)yOLApVj
} IyOujdKa
else =/.[&DG
break; zi2hi9A
} #PoUCRRC
} #1z}~1-
catch(IOException e){e.printStackTrace ();} :Ff1Js(Z
catch(Exception e){e.printStackTrace ();} q{@>2AlK
vBj{bnl
U;OJ.a9
Utility.log(nFileLength); /,2Em>
/4w&! $M-
r&0v,WSp&S
return nFileLength; `"I^nD^t>Y
} M<"&$qZ$R
\M="R-&b
e_g7E+6
//保存下载信息（文件指针位置） >8t3a-/
private void write_nPos() Wh(V?!^@5
{ O9p8x2
try{ `P)atQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); oO$a4|&,
output.writeInt(nStartPos.length); H1 n`A#6?
for(int i=0;i<nStartPos.length;i++) AmRppbj/wO
{ 1A< O Z>
// output.writeLong(nPos); `DC)U1
output.writeLong(fileSplitterFetch.nStartPos); Jmf&&)p
output.writeLong(fileSplitterFetch.nEndPos); A"I:cw"KY
} @4T+0&OI10
output.close(); $}aLFb
} wR@fB
catch(IOException e){e.printStackTrace ();} n_)d4d zl
catch(Exception e){e.printStackTrace ();} Ts|&_|
} i~n>dc YW
]|Vm*zO
p/cVQ
//读取保存的下载信息（文件指针位置） QlSZr[^v
private void read_nPos() :I+%v
{ 9@Cqg5Kx'
try{ FoInJ(PDH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -_%n\#
int nCount = input.readInt(); B+*F?k[
nStartPos = new long[nCount]; F4e<=R
nEndPos = new long[nCount]; :?U1^!$$1
for(int i=0;i<nStartPos.length;i++) Sl
{ )`,3/i9C$
nStartPos = input.readLong(); z./u;/:
nEndPos = input.readLong(); (YGJw?]
} 71@V|$Dy
input.close(); X@\rg}kP
} )C<c{mjk(
catch(IOException e){e.printStackTrace ();} L@ql)Lc);
catch(Exception e){e.printStackTrace ();} n3g3(}Q0
} RoJ{ ou@cs
0V}%'Ec<e
4@4$kro
private void processErrorCode(int nErrorCode) 2Af1-z^^K
{ cIw)ScY
System.err.println("Error Code : " + nErrorCode); R}#?A%,*
} H8mmmt6g
wZ0$ylEX
TC<_I0jCh
//停止文件下载 "/(J*)%{
public void siteStop() KaauX m
{ ,&Gn7[<
bStop = true; (caxl^=
for(int i=0;i<nStartPos.length;i++) bsmZR(EnU
fileSplitterFetch.splitterStop(); Vge9AH:op
O< v0{z09*
#B88w9 b`D
} %S. _3`A
} MQG(n+c
//负责部分文件的抓取 .Qyq*6T3&
**FileSplitterFetch.java G yvEc3|@
*/ 7s4G|N[wR\
package NetFox; d!D#:l3;
0/6f9A
K pDKIi
import java.io.*; ey_3ah3x
import java.net.*; 5*/~) wN\U
$>hPB[[
Y^M3m'd?
public class FileSplitterFetch extends Thread { [o<Rgq4
etMQy6E\
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String sURL; //File URL CCNrjaA
long nStartPos; //File Snippet Start Position p`fUpARA!
long nEndPos; //File Snippet End Position j_H9l,V
int nThreadID; //Thread's ID W;4rhZEgd
boolean bDownOver = false; //Downing is over M2W4 RovfR
boolean bStop = false; //Stop identical Sb+^~M
FileAccessI fileAccessI = null; //File Access interface i+ ]3J/J
ZP &q7HK\
)"/.2S;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s/"&k
{ $M5iU@A
this.sURL = sURL; J: vq)G\F
this.nStartPos = nStart; {0RwjPYp
this.nEndPos = nEnd; ,bzE`6
nThreadID = id; e{EKM4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Q'5]E{1<'n
} ^hr^f;N
"Rr)1x7
-+?ZJ^A
public void run() T1%_sq
{ Rsd~t_a1
while(nStartPos < nEndPos && !bStop) ,P ~jO
{ 1Bp?HyCR
:%7y6V*
@rI+.X
try{ !k@(}CN_*
URL url = new URL(sURL); 5, "
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >!sxX = <
httpConnection.setRequestProperty("User-Agent","NetFox"); o5LyBUJ
String sProperty = "bytes="+nStartPos+"-"; =hFIH\x
httpConnection.setRequestProperty("RANGE",sProperty); 7IkNS
Utility.log(sProperty); 3w!8PPl
lt08 E2p9
xKl\:}Ytp
InputStream input = httpConnection.getInputStream(); ^x2zMB\t
//logResponseHead(httpConnection); K93L-K^J
Cq8.^=}_
X!,huB^i
byte[] b = new byte[1024]; FxU a5n
int nRead; j/ [V<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rf?%- X(V
{ AS4mJ UU9
nStartPos += fileAccessI.write(b,0,nRead); Q~k5 }n8
//if(nThreadID == 1) ":@\kw
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); | KtI:n4d
} B']-4X{SGa
UOIB}ut V
>PuQ{T I
Utility.log("Thread " + nThreadID + " is over!"); J4?i\wD:
bDownOver = true; boS=
//nPos = fileAccessI.write (b,0,nRead); w1Txz4JqB
} 6 &Lr/J76
catch(Exception e){e.printStackTrace ();} @cB7tY*Ski
} 0:I[;Qt
} AjVX
_=Z?5{7S>
:A7\eN5
//打印回应的头信息 =xw+cs1,x
public void logResponseHead(HttpURLConnection con) %lq[,6?>5
{ -\<\OV:c*
for(int i=1;;i++) 9U>OeTh(
{ .Ht;xq
String header=con.getHeaderFieldKey(i); "UX/yLc3(
if(header!=null) 7F2 WmMS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +Jm~Um!
Utility.log(header+" : "+con.getHeaderField(header)); 1-V"uLy@gC
else -w"$[XP
break; s Poh\n
} : &bJMzB
} BItH0r7
5G2G<[p5oQ
:6MV@{;PJ
public void splitterStop() 6l'J!4*qY
{ 3{)!T;Wd
bStop = true; =MU(!`
} OxQ5P;O
&@K6;T
d.|*sZ&3p
} 9(3]t}J5 d
sZI"2[bk
7KesfH?
/* QJ&]4*>a
**FileAccess.java q68CU~i*
*//文件访问(定位，写) E.%V0}
package NetFox; Lk)I;;
import java.io.*; 0!-'4+"
5tyA{&Ao
3! #|hI>f
public class FileAccessI implements Serializable{ up{0ehr
o}DRp4;Ka
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4> uNH5
RandomAccessFile oSavedFile; T+^Sa J
long nPos; [>N#61CV5
ht*N[Pi4;
idB1%?<
public FileAccessI() throws IOException @0]w!q
{ ~/X8Hy!-
this("",0); Ni8%K6]z
} udT0`6l;
_CPj]m{
@<3E`j'p
public FileAccessI(String sName,long nPos) throws IOException Mq#m;v$E
{ '<3h8\"
oSavedFile = new RandomAccessFile(sName,"rw"); j85B{Mab&
this.nPos = nPos; w[F})u]E
oSavedFile.seek(nPos); ]isq}Qv~
} s>:gL,%c
\s%g'g;
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public synchronized int write(byte[] b,int nStart,int nLen) k,$/l1D
{ Rz&`L8Bz
int n = -1; %X's/;(Lx`
try{ g4=C]\1
oSavedFile.write(b,nStart,nLen); 0J^Z)U>j
n = nLen; Dt<MEpbur
} A +=#
catch(IOException e) 9+MW13?
{ c]Gs{V]\
e.printStackTrace (); %19~9Tw
} !yT=*Cj4
_p0gXb1m`
tvf5b8(Y-
return n; b1>]?.
} B8eZ}9X
V,rR*a&p
P>u2""c
} p+<qI~
w>\oz
,"5HJA4
/* ,tQNL\t
**SiteInfoBean.java Go1xyd:k
*/ utRO?]%d !
package NetFox; 50dN~(;p
J~xm[^0
@{#'y4\>
public class SiteInfoBean { kssRwe%>;
@67GVPcxl
q+4dHS)x
private String sSiteURL; //Site's URL *Gv:N6
private String sFilePath; //Saved File's Path X.>~DT%0Lm
private String sFileName; //Saved File's Name % >a /m.$
private int nSplitter; //Count of Splited Downloading File 8 e_]
ern\QAhXX
+|b#|>6
public SiteInfoBean() JL!^R_b&c
{//nSplitter的缺省值为5 ~:k r;n2
//default value of nSplitter is 5 ^wc:qll
this("","","",5); shL_{}
} o/ 51RH
@YRy)+
k&:q|[N
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) w8~R=k
{ bf=\ED^
sSiteURL= sURL; #g@4c3um|
sFilePath = sPath; $<XQv$YS
sFileName = sName; ?./fVoA]V
this.nSplitter = nSpiltter; o\ce|Dzt
h8%QF'C
%scIZCrI~
} A@?-"=h}
!5h-$;
Ac{TqiIv
public String getSSiteURL() ~|, "w90
{ *Q?8OwhJ
return sSiteURL; Pzd!"Gl9
} oiR9NB&<
"[k>pzl6
5M9o(Z\AF
public void setSSiteURL(String value) ]8OmYU%6V
{ D3,)H%5.y
sSiteURL = value; 6< -Cpc
} Il>o60u1
gBWr)R
/qwY/^
public String getSFilePath() ar 7.O;e
{ AB0}6g^O
return sFilePath; TG8U=9qt
} vg3iT}
jA2%kX\6//
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public void setSFilePath(String value) D-t!{LA
{ i"Hc(lg
sFilePath = value; ToKG;Ff4b
} K0o${%'@7
Ktt(l-e+
x $[_Hix
public String getSFileName() &}C-W* f,Z
{ dblf,x
return sFileName; DnhbMxh8o
} E@)'Z6r1
-$#2?/uqC
U|.r -$|5P
public void setSFileName(String value) )K::WqR%w)
{ nQ|($V1?W
sFileName = value; (E,[Ad,$
} 1^GRUbOU[
l O*
[4bE"u
public int getNSplitter() S=`$w
{ 3m4 sh~
return nSplitter; snu?+*6
} 5A5t
Btr>ek
8KkN "4'
public void setNSplitter(int nCount) _*{Lha
{ U7g,@/Qx
nSplitter = nCount; 3fX_XH1Q
} IZ^:wIKo{
} a+O?bO
1=9GV+`n
(|<+yQ,@>
/* car|&b
**Utility.java >o`+j$j
*/ #4"eQ*.*"
package NetFox; Uugq.'>
UmMu|`
Ku uiU= (L
public class Utility { 8:*ZuR|~
kSCpr0c
Zy?!;`c*{
public Utility() :9x]5;ma
{ -byaV;T?"
FjiIB1 T
7i02M~*uS
} S5Pn6'w
hcYqiM@8>
//线程睡眠 +;pw^QB
public static void sleep(int nSecond) Lc]hwMGR*
{ w~pe?j_F$
try{ QGGBI Ku
Thread.sleep(nSecond); U#w0E G
} iYw1{U
catch(Exception e) ]-a/)8
{ n+<
e.printStackTrace (); Nr)DU.f
} MU `!sb*
} ER[$TH&
60e{]}Z
//日志 x5;D'Y t"|
public static void log(String sMsg) 5 /oW/2"
{ M_cm,|FF
System.err.println(sMsg); /!6 VP |
} nG?Z* n
l>BM}hS
~+Cl9:4T
public static void log(int sMsg) @(N} {om
{ 4&e<Sc64
System.err.println(sMsg); };Df ><
} I.~=\%Z{
} 0lOan
6e5A8e8"]
_Vt9ckaA
/* oz|+{b}%
**TestMethod.java i/!KUbt
*/ Q4S:/"*v8
package NetFox; [x`),3qD
*] >R
k{|>!(Ax
public class TestMethod { pRsIi_~&
-sDl[
~qTChCXP
public TestMethod() NQiu>Sg
{ ///xx/weblogic60b2_win.exe KRP6b:+4L
try{ &Akw V-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); I?\P^f
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g@?R"
SiteFileFetch fileFetch = new SiteFileFetch(bean); wk^$DM/KJ)
fileFetch.start(); '*&V7:
} W!=ur,F+
catch(Exception e){e.printStackTrace ();} |GPYbxzc
c0X1})q$
SF ^$p$mC
} Pe11azJ
zpNt[F?~1
GQjU="+
public static void main(String[] args) *8u<?~9F
{ LJ z6)kz
new TestMethod(); \t&8J+%
} kaECjZ_&+
} {8%KO1xB
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