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)); B;K{Vo:C
} ![vc/wuf
for(int i=0;i<nEndPos.length-1;i++) G&uj}rj
{ YF:NRY[i
nEndPos = nStartPos[i+1]; zkd#vAY(A
} 10[~ki-1;
nEndPos[nEndPos.length-1] = nFileLength; MfL q h
} "lz!'~im
} T|{BT! W1E
4a3f!G$
!Uj !Oy
//启动子线程 6iC}%eU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yRgo1ow]
for(int i=0;i<nStartPos.length;i++) 9J|YP}%
{ yNDyh
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Vy/g;ZPU1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C8t+-p
nStartPos,nEndPos,i); H@ w6.[#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aIfog+Lp
fileSplitterFetch.start(); Hou{tUm{xC
} O]PfQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dT|z)-Z`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >`NM?KP s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", PO}Q8Q3
nEndPos = " + nFileLength); )5&m:R9
// fileSplitterFetch[nPos.length-1].start(); RB\WttI
E""/dC:B
9|e"n|[
//等待子线程结束 &U,f~KJ
//int count = 0; I{Kc{MXn
//是否结束while循环 b%_QL3m6
boolean breakWhile = false; i5wA=K_
34?yQX{
)RkU='lB "
while(!bStop) qB=pp!zQ
{ Q72wg~%w
write_nPos(); b\+|g9Tm
Utility.sleep(500); yf8UfB#a
breakWhile = true; XWvs~Xw@
JZv]tJWq
Lhc@*_2
for(int i=0;i<nStartPos.length;i++) $yc,D=*Isi
{ s<dD>SU
if(!fileSplitterFetch.bDownOver) cp2fDn
{ $e;!nI;z
breakWhile = false; q+:(@w6
break; QbNv+Eu5
} (o:CxhV
} >4VU
if(breakWhile) ,mX|TI<*
break; m0* B[
FEZ6X
mQvKreo~
//count++; 395o[YZx*
//if(count>4) X or ,}. w
// siteStop(); -#o+x Jj
} 6f>l~$
v-gT 3kJ
qB39\j
System.err.println("文件下载结束！"); h@~X*yLKh
} :^s7#4%6
catch(Exception e){e.printStackTrace ();} _l,Z38
} {UmCn>c
dbuOiZ
'f}S,i +q
//获得文件长度 *0hiPj:
public long getFileSize() @r]s9~Lx9
{ 7gMtnwT
int nFileLength = -1; iy#OmI>j
try{ z-gwNE{
URL url = new URL(siteInfoBean.getSSiteURL()); u`'z~N4}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4@V]zfu^Q
httpConnection.setRequestProperty("User-Agent","NetFox"); eq+o_R}CS
Ntnmd
{^kG<v.vV
int responseCode=httpConnection.getResponseCode(); 0;h1LI)
if(responseCode>=400) iXm||?Rnx
{ [4hO3):F
processErrorCode(responseCode); NslA/"*
return -2; //-2 represent access is error +.lWck
} :]^P^khK
h3lDDyu
W^ :/0WR
String sHeader; B#?2,
yUW&Wgc=:
e] K=Nm
for(int i=1;;i++) M',D
{ iW}l[g8sw!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8-"5|pNc
//Utility.log(in.readLine()); y,&M\3A
sHeader=httpConnection.getHeaderFieldKey(i); icul15'i
if(sHeader!=null) .G_3blE;
{ i+[3o@
if(sHeader.equals("Content-Length")) GeaDaYh#T
{ b H?qijrC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); dl6v <
break; gc@#O#K~h^
} ~{vdP=/WP
} yJ8}*Gj&
else 3> #mO}\
break; P"x-7>c>Y
} ZGpTw[5ql
} 5g1M_8e'+
catch(IOException e){e.printStackTrace ();} e4Ox`gLa*p
catch(Exception e){e.printStackTrace ();} <i'u96
S[~O')
eq~c
Utility.log(nFileLength); [Hj'nA^
@qPyrgy
A3$aMCwKd
return nFileLength; 0R}Sw[M.
} |R;l5ZKvV
ZSRRlkU
V`\f+Uu
//保存下载信息（文件指针位置） l^!A
private void write_nPos() *?bk?*?s
{ 6"i{P
try{ e[QxFg0E
output = new DataOutputStream(new FileOutputStream(tmpFile)); PiQkJ[
output.writeInt(nStartPos.length); XalJo@%-
for(int i=0;i<nStartPos.length;i++) tP`G]BCbt
{ c',:@2R
// output.writeLong(nPos); `(,*IK a
output.writeLong(fileSplitterFetch.nStartPos); [2'm`tZL
output.writeLong(fileSplitterFetch.nEndPos); z,bX.*.-
} z]c,}Q
output.close(); +`*qlP;
} @yt2_
catch(IOException e){e.printStackTrace ();} t0bhXFaiE
catch(Exception e){e.printStackTrace ();} ;tp]^iB#
} u`Z0{d
#P%1{l5m
H^D 3NuUC
//读取保存的下载信息（文件指针位置） =_RcoG/^~
private void read_nPos() ypD<2z^
{ $_RWd#Q(
try{ VW9>xVd4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9q1HSJ1)
int nCount = input.readInt(); 7}ws |4Y
nStartPos = new long[nCount]; f v E+.{
nEndPos = new long[nCount]; Fm<jg}>MAd
for(int i=0;i<nStartPos.length;i++) y9C;T(oi;
{ QqiJun_m
nStartPos = input.readLong(); O3kg
nEndPos = input.readLong(); o_Jn_3=
} a)!![X?\
input.close(); uu}`warW
} ><NI'q*cQ
catch(IOException e){e.printStackTrace ();} d>%gW*
catch(Exception e){e.printStackTrace ();} &8<<!#ob
} =db'#m{$
7/H^<%;y
-t8hi+NK
private void processErrorCode(int nErrorCode) Oj4v#GK]
{ gjj 93
System.err.println("Error Code : " + nErrorCode); `$s)X$W?
} 0xJ7M.
k"xGA*B|
2+?T66 g
//停止文件下载 8Y2xW`
public void siteStop() pheE^jUr
{ #`W=mN(+k
bStop = true; *cbeyB{E
for(int i=0;i<nStartPos.length;i++) P$Z}
fileSplitterFetch.splitterStop(); ,E\h!/X
lVPOYl%
w8O" =},
} T~BA)![
} *7ZGq(O
//负责部分文件的抓取 4/S=5r}
**FileSplitterFetch.java sI_7U^"[
*/ [r)eP({
package NetFox; !p9)CjQ"
N0i!l|G6
>F1G!#$0
import java.io.*; /~De2mq1
import java.net.*; 9lf*O0Z&n
BZK2$0
HPrq1QpK
public class FileSplitterFetch extends Thread { uG!:Z6%p
{7*>Cv}
$ a?
String sURL; //File URL >M]6uf
long nStartPos; //File Snippet Start Position qve ./
long nEndPos; //File Snippet End Position "#yJHsu]
int nThreadID; //Thread's ID j~;;l!({i
boolean bDownOver = false; //Downing is over MJ`N,E[
boolean bStop = false; //Stop identical ^W~p..DF
FileAccessI fileAccessI = null; //File Access interface A /(lKq
T*?s@$)m4
Lxv6!?v|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }bH$O%
{ UiH!Dl}<
this.sURL = sURL; J'b<z.OW
this.nStartPos = nStart; $&{ti.l
this.nEndPos = nEnd; =pcF:D#+
nThreadID = id; !gF9k8\Yr$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Xa," 'r
} qFco3
j%L&jH6@
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public void run() Z&Y=`GOI
{ \\06T`
while(nStartPos < nEndPos && !bStop) \8S~c8Z~
{ D-2.fjo9!
gn8|/ev
eujK4s
try{ LJFG0 W
URL url = new URL(sURL); P?LlJ5hn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QzOkpewf
httpConnection.setRequestProperty("User-Agent","NetFox"); MP^ d}FL
String sProperty = "bytes="+nStartPos+"-"; ,HB2hHD
httpConnection.setRequestProperty("RANGE",sProperty); ujFzJdp3k
Utility.log(sProperty); zce`\ /:
oR .cSGh
)w h%|
InputStream input = httpConnection.getInputStream(); cc}Key@D
//logResponseHead(httpConnection); DC+b=IOz
GsQ*4=C
G(iJi
byte[] b = new byte[1024]; >j*;vG5T
int nRead; 'sh~,+g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r%@Lej5+
{ s 5WqR8
nStartPos += fileAccessI.write(b,0,nRead); urBc=3Rz
//if(nThreadID == 1) tZyo`[La
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^qGb%! l
} Fmyj*)J[Z
*\}}Bv+9
g{IF_ 1
Utility.log("Thread " + nThreadID + " is over!"); hR#-u1C
bDownOver = true; d}'U?6ob
//nPos = fileAccessI.write (b,0,nRead); = ?D(g
} V7d)S&*V
catch(Exception e){e.printStackTrace ();} $ _j[2EU
} cD*}..-/4
} fKH7xu!V4+
<%.5hCTp97
3`E=#ff%
//打印回应的头信息 /X"/ha!=&D
public void logResponseHead(HttpURLConnection con) E>b2+;Jv
{ N`@NiJ(O;
for(int i=1;;i++) e^p +1-B
{ $YxBE`)d-
String header=con.getHeaderFieldKey(i); KWAb-yB
if(header!=null) )J]9 lW&y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @"a6fn
Utility.log(header+" : "+con.getHeaderField(header)); N`iwC!
else :x.7vZzxs
break; ]i(-I <`
} m>USD?i
} [(Xy.L7x
!+>v[(OzM
-9N@$+T
public void splitterStop() =_$Qtq+h
{ -;f*VM.a
bStop = true; P-F)%T[
} |4$M]Mf0
&'cL%.
theZ]5_C
} 8fA_p}wp
sn7AR88M;
=qN2Xg/
/* b0iSn#$
**FileAccess.java #/PAA
*//文件访问(定位，写) R1Sy9x .
package NetFox; coYij
import java.io.*; 5F`;yh+e
RMMd#/A@}
DN4$Jva
public class FileAccessI implements Serializable{ d%l{V6
t78k4?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s4&^D<
RandomAccessFile oSavedFile; {vAE:W.s
long nPos; 9x,RvWTb
hig2
8~5cJPi6
public FileAccessI() throws IOException C9p"?vX
{ hiNEJ_f
this("",0); f~}H
} gZ5[ C
J2uZmEt
N !TW!
public FileAccessI(String sName,long nPos) throws IOException =8U&[F
{ qI^ /"k*5
oSavedFile = new RandomAccessFile(sName,"rw"); kdGT{2u
this.nPos = nPos; t&?im<
oSavedFile.seek(nPos); $9?cP`hmi
} R8.CC1Ix
0uBl>A7qhn
{Zp\^/
public synchronized int write(byte[] b,int nStart,int nLen) 5dZ|!
{ \QmCeB
int n = -1; ;WldHaZ9r
try{ qCv20#!"|
oSavedFile.write(b,nStart,nLen); ,t1abp{A
n = nLen; }NsUnbxT
} J,b&XD@m
catch(IOException e) >[X{LI(_<<
{ jsNF#yE>
e.printStackTrace (); "s\L~R.&
} 28 3H
$0arz{Oh
,m,)I
return n; m*mm\wN5
} _'#x^D
NKQOUw:qn
E= `6-H{
} ZY:[ekm%4Z
@^uH`mc
['ksP-=
/* =|=.>?t6Z0
**SiteInfoBean.java s`#(
*/ p019)X|vx
package NetFox; [CAR[ g&
C)cwAU|h#
$y b4xU
public class SiteInfoBean { 'g9"Qv?0{`
@u1zB:
5aa<qtUjH
private String sSiteURL; //Site's URL ;U_QvN|
private String sFilePath; //Saved File's Path )Z %T27r,^
private String sFileName; //Saved File's Name Kt(-@\)!
private int nSplitter; //Count of Splited Downloading File bMU(?hb
WKSPBT;
VM0j`bs'K*
public SiteInfoBean() \cCV6A[
{//nSplitter的缺省值为5 8|$3OVS
//default value of nSplitter is 5 /x1MPP>fu
this("","","",5); 5y?-fT]X
} ?Mee 6
$U/YR&vcw
O2"gj"D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pD&&l!i&[
{ (#;`"Yu
sSiteURL= sURL; *cO sv
sFilePath = sPath; -J^(eog[6
sFileName = sName; @&}q}D
this.nSplitter = nSpiltter; {?`al5Sz
;.bm6(;
]f1{n
} n>'Kp T9|
z'`y,8Y1l
;vb8G$
public String getSSiteURL() IVW1]y
{ _FwK-?4E-
return sSiteURL; TFcT3]R[rL
} CR|lt
Q#EP|
i9=&;_z
public void setSSiteURL(String value) l|hUw
{ *x)8fAr
sSiteURL = value; gI8Bx]
} Uw4>v:
IMk'#)
!|<=ZF2
public String getSFilePath() R CkaJ3
{ 95<EN(oUD
return sFilePath; hTbI -u7BF
} 4Yl;
Sc7U|s
7+hK~
public void setSFilePath(String value) d`1I".y
{ HD N9.5S
sFilePath = value; =f(cH152T
} BW,mwq
( 9]_ HW[
[V 8{b{
public String getSFileName() b}Zd)2G
{ .] `f,^v<c
return sFileName; `CeJWL5{
} "YB**Y
jzK5-;b
2<hpK!R
public void setSFileName(String value) 9!><<7TS
{ &[&r2>a
sFileName = value; sN("+ sZ.n
} ?h!i0Rsm
H}LS??P
Z/ Tm)Xd
public int getNSplitter() DI;DECQl$
{ 2!Bd2
return nSplitter; #Oha(mRY
} pMs AyCAk
5E0eyW
xF8}:z0
public void setNSplitter(int nCount) R1Ye<R!Q
{ Iyo@r%I
nSplitter = nCount; =YG _z^'
} `HuCT6O
} %okzOKKX
CU7F5@+
.`CZUKG
/* z_ =Bt
**Utility.java I!wX[4p eg
*/ KgW:@X7wvM
package NetFox; 8L*GE
mA7m
DKVT(#@T
public class Utility { "G:<7oTa
it2 a
[j4v]PE
public Utility() )+H[kiN
{ +wW@'X
""svDfy$
+PK6-c\r
} _W3Y\cs,-
IcIOC8WC
//线程睡眠 *1@:'rJ
public static void sleep(int nSecond) 8^B;1`#
{ A>VX*xd
try{ Dr;iQkGP
Thread.sleep(nSecond); IHC1G1KW=A
} =e?$M
catch(Exception e) /#<pVgN
{ ~L7:2weV[
e.printStackTrace (); LEECW_:
} xLZd!>C
} wY"o`oZ
s/Xb^XjS1
//日志 7<9L?F2
public static void log(String sMsg) :c8n[+5
{ ^zEE6i
System.err.println(sMsg); (cv!Y=]
} V[a[i>,Z
/XS&d%y
m=qOg>k
public static void log(int sMsg) 0uCT+-
{ uIMe
System.err.println(sMsg); =8=!Yc(>
} pUl8{YGS
} +rWZ|&r%
p4VSma_(
*R% wUi
/* T}7uew\v0<
**TestMethod.java }%{MPqg
*/ y33~HsOJ
package NetFox; q6`GI6
=neL}Fav56
y|_Eu:
public class TestMethod { ep(g`e
[FQ\I-GNC
"Mmf6hu
public TestMethod() t^EhE
{ ///xx/weblogic60b2_win.exe }gf}eH
try{ ZEbLL4n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lu UYo
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); MEwdw3
SiteFileFetch fileFetch = new SiteFileFetch(bean); \)m"3yY
fileFetch.start(); 6-,m}Ce\
} Ua*&_~7kJ
catch(Exception e){e.printStackTrace ();} m(sXk}e;1
fMK#x\.4
Gk~l,wV>
} Qu{cB^Ga*
8 |h9sn;P
(&&87(
public static void main(String[] args) +lO'wa7|3
{ 3/M.0}e
new TestMethod(); fAj2LAK
} 4f1D*id*`#
} xQt 3[(Z
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