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)); 5z@QAQ
} (&oT6Ji
for(int i=0;i<nEndPos.length-1;i++) Ch7&9NW
{ Np>0c-S
nEndPos = nStartPos[i+1]; 0ra+MQBg
} K/|qn)
nEndPos[nEndPos.length-1] = nFileLength; 6r}w
} )Kg_E6
} WF`
`XK#sCC
=g<Y[Fi2
//启动子线程 G&@vTcF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U{ZKxE
for(int i=0;i<nStartPos.length;i++) Je#vu`.\\
{ o0#zk
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QR(j7>+J^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), U{PFeR,Uk
nStartPos,nEndPos,i); G^A}T3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'tMS5d)4:
fileSplitterFetch.start(); ~'t+X
} T~)zgu%q_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (F'?c1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4{#0ci{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =e|
nEndPos = " + nFileLength); 3im2 `n
// fileSplitterFetch[nPos.length-1].start(); .y2np
&U{"dJr
G ;
//等待子线程结束 laA3v3*
//int count = 0; uV\~2#o$_
//是否结束while循环 P;[>TCs ]8
boolean breakWhile = false; \5R>+[n!
dZ"d`M>o6
V2BsvR`
while(!bStop) {^6<Ohe4j
{ Q)ZbnR2Z8
write_nPos(); Ahrtl6@AS
Utility.sleep(500); -< }#ImTN
breakWhile = true; M =6
Vo(V<2lw}
HRW}Yl
for(int i=0;i<nStartPos.length;i++) Rv@( [rn+
{ Fu"@)xw/-q
if(!fileSplitterFetch.bDownOver) _{48s8V
{ W;ADc2#)
breakWhile = false; 7oFA5T _
break; ^9 {r2d&c
} <hzuPi@
} wZ\% !#}7
if(breakWhile) T(iL#2^
break; 0uO<7IW9
d{~Qd|<rr
vC_O!2E
//count++; "7_qB8\
//if(count>4) nQM7@"R
// siteStop(); ,7*-%05[\
} Nj|~3 *KO
q.69<Rs
["XS|"DM
System.err.println("文件下载结束！"); iYl$25k/1
} Ll'!aar,
catch(Exception e){e.printStackTrace ();} +d/^0^(D\5
} u}BN)%`B
I<L<xwh1(E
;+4X<)y*>
//获得文件长度 S[L2vM)
public long getFileSize() C!J6"j
{ Cd51.Sk(l
int nFileLength = -1; 0fU^
try{ i"U<=~
URL url = new URL(siteInfoBean.getSSiteURL()); :h)A/k_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U&<w{cuA
httpConnection.setRequestProperty("User-Agent","NetFox"); nO7#m~
ZeP3 Yjr3
&4-rDR,
int responseCode=httpConnection.getResponseCode(); 8GFA}_(^R
if(responseCode>=400) >"z&KZKI
{ +jpC%o}C
processErrorCode(responseCode); B^sHFc""V
return -2; //-2 represent access is error @dp1bkU
} SK_i 3?
20p/p~<
PM!7ci
String sHeader; a?QDf5Cq
60St99@O
8ncgTCH:
for(int i=1;;i++) Nd.Tda!Kg
{ /o=,\kM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fG\]&LFBU
//Utility.log(in.readLine()); 0kB!EJ<OdG
sHeader=httpConnection.getHeaderFieldKey(i); M=aWL!nJ
if(sHeader!=null) 3U73_=>=&
{ `nDgwp:b"
if(sHeader.equals("Content-Length")) I+^B]@"
{ %aeQL;# V
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Bz#K_S
break; c(<,qWH
} -O=a"G=
} uKZe"wN;
else k$7@@?<
break; (~>L \]!
} &i~AXNw
} ~CB6+t>
catch(IOException e){e.printStackTrace ();} H.ZmLB
catch(Exception e){e.printStackTrace ();} "wPFQXU
OgTE^W@
buhn~ c
Utility.log(nFileLength); Q(2X$7iRq
w*Gv#B9G
KR6*)?c`
return nFileLength; <k^P>Irb3t
} 5M{DJ/q
syYg, G[
!m#cneV
//保存下载信息（文件指针位置） Gd~Xvw,u
private void write_nPos() !$>d75zli
{ ZL`G<Mo;.
try{ #(53YoV_8
output = new DataOutputStream(new FileOutputStream(tmpFile)); o2 5kFD
output.writeInt(nStartPos.length); }Vpr7_
for(int i=0;i<nStartPos.length;i++) ogX'3L
{ q)ygSOtj
// output.writeLong(nPos); q($lL~Ls
output.writeLong(fileSplitterFetch.nStartPos); K'%,dn
output.writeLong(fileSplitterFetch.nEndPos); v?yHj-
} _gY so]S^B
output.close(); 1@Bq-2OD4
} S#X$QD
catch(IOException e){e.printStackTrace ();} z+1#p.F$@
catch(Exception e){e.printStackTrace ();} hgE!)UE
} $.}fL;BzVz
?J+[|*'yK
.BXZ\r`
//读取保存的下载信息（文件指针位置） /c`)Er6d
private void read_nPos() WIo^=?%
{ "RH2%
try{ Etj*3/n|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ";j/k9DE
int nCount = input.readInt(); Mz<4P3"H
nStartPos = new long[nCount]; LS?hb)7
nEndPos = new long[nCount]; &{* [7Ad
for(int i=0;i<nStartPos.length;i++) 8^zI
{ qyc:;3?wm
nStartPos = input.readLong(); iLy}G7h
nEndPos = input.readLong(); xkOyj`IS
} (^eSm]<
input.close(); A5Yfm.Jy
} @4h .?
catch(IOException e){e.printStackTrace ();} W k'()N
catch(Exception e){e.printStackTrace ();} 4D[W;4/p
} Qg?^%O'
s_K:h
!$St=!
private void processErrorCode(int nErrorCode) kAf:_0?6
{ J']1^"_'
System.err.println("Error Code : " + nErrorCode); l{aXX[E&1
} Qm,|'y:Tg
}MrRsvN
R{@WlkG}
//停止文件下载 ?`,UW;Br6
public void siteStop() *gu~7&yoP
{ zF(I#|Vo
bStop = true; eqs.zL
for(int i=0;i<nStartPos.length;i++) }9>W41
fileSplitterFetch.splitterStop(); G(|ki9^@"9
NXDdU^w7B
sju. `f>-r
} N(]6pG=
} `pm6Ts{,
//负责部分文件的抓取 Fc7mAV=
**FileSplitterFetch.java >I8R[@
*/ +Ld4e]
package NetFox; o{?s\)aBa
U9IN#;W
0~R0)Q,
import java.io.*; br>"96A1l
import java.net.*; a*NcL(OC
X|7gj&1
tV@!jaj\
public class FileSplitterFetch extends Thread { B@A3T8'
)O"5dF1l
$dgY#ST%
String sURL; //File URL ;a XcGa
long nStartPos; //File Snippet Start Position gx#xB8n
long nEndPos; //File Snippet End Position HzF
int nThreadID; //Thread's ID 55Y BO$
boolean bDownOver = false; //Downing is over #)tt}GX
boolean bStop = false; //Stop identical gsqlWfa
FileAccessI fileAccessI = null; //File Access interface ^|Of
x;99[C!$
hoD (G X
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ),mKEpf
{ w{UVo1r:
this.sURL = sURL; ~M3`mO+^U
this.nStartPos = nStart; H.hF`n
this.nEndPos = nEnd; ,Za!
nThreadID = id; mMS%O]m,|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :&HrOdz
} Z[RE|l{
6x^#|;e>lI
(g`G(K_
public void run() ;x$,x-
{ f6j;Y<}' g
while(nStartPos < nEndPos && !bStop) uwXquOw
{ B?`Gs^Y{z
s%2w&Us*
uK6R+a
try{ casva;
URL url = new URL(sURL); NBwxN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [KLs} ~H
httpConnection.setRequestProperty("User-Agent","NetFox"); l<>syHCH;L
String sProperty = "bytes="+nStartPos+"-"; P%A;EF~v
httpConnection.setRequestProperty("RANGE",sProperty); (/Lo44wT
Utility.log(sProperty); =&;orP
LuM:dJ
\1cay#X
InputStream input = httpConnection.getInputStream(); ijEMS1$=7
//logResponseHead(httpConnection); ?& qMC
XZD9vFj1Z
[nZf4KN
byte[] b = new byte[1024]; T2<?4^xN
int nRead; tPBr{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j*+[=X/
{ |T\`wcP`q
nStartPos += fileAccessI.write(b,0,nRead); @/FE!6 |O
//if(nThreadID == 1) z SDRZ!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]rGZ
} E}LuWFZ&
_;L%? -2c
VPW@y
Utility.log("Thread " + nThreadID + " is over!"); }N[|2nR'
bDownOver = true; `Sgj!/!F
//nPos = fileAccessI.write (b,0,nRead); B( r~Nvc
} O{b<UP'85
catch(Exception e){e.printStackTrace ();} H3\4&q
} 1Tl^mS~k
} +yYxHIOZ(
p}H:t24Cr5
(mbC! !>
//打印回应的头信息 =h5&:?X
public void logResponseHead(HttpURLConnection con) R9XISsM^
{ [PG#5.jwQ
for(int i=1;;i++) >f+qImH
{ &U*MLf83`
String header=con.getHeaderFieldKey(i); lw+Y_;
if(header!=null) eb1WTK@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }_Y&kaM
Utility.log(header+" : "+con.getHeaderField(header)); o]T-7Gs4p
else VWhq+8z
break; QFekj@
} oKyl2jg+,
} cdd6*+E
qZQB"Q.*
rtM29~c>@
public void splitterStop() yM,.{m@F<
{ WO;2=[#O;
bStop = true; ZkWX4?&OMt
} U$,-F**
[A jY~
OVq(ulwi+
} 9 +1}8"~
*2,tGZ
\B/!}Tn;
/* GZxPh&BM?
**FileAccess.java @kstG3@
*//文件访问(定位，写) ATRB9
package NetFox; 9U]3B)h%m
import java.io.*; FTgqE@
idzc4jR6BT
shkyN
public class FileAccessI implements Serializable{ eP(|]Rk
DhVO}g)2#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2I[(UMI$7
RandomAccessFile oSavedFile; 1S{AGgls5
long nPos; /Fj*sS8
c)`=wDi
tD^$}u6
public FileAccessI() throws IOException qs$w9I
{ 'Lu d=u{
this("",0); F:~k4uTW\b
} pQ,|l$^m
Mg~62u
o? LJ,Z
public FileAccessI(String sName,long nPos) throws IOException ]Uj7f4)k
{ ]mR!-Fqj
oSavedFile = new RandomAccessFile(sName,"rw"); 0<[g7BbR
this.nPos = nPos; )+ (GE
oSavedFile.seek(nPos); 1j_ 6Sw(
} $Wn!vbL
0/5{v6_rG
Xmny(j)g
public synchronized int write(byte[] b,int nStart,int nLen) 1v~1?+a\2
{ 9,jFQb(),
int n = -1; ~ugyUpY"
try{ 'H8b+
oSavedFile.write(b,nStart,nLen); "'3QKeM1
n = nLen; jPIOBEIG
} 5~FXy{ZIH
catch(IOException e) <4:%M
{ cGM?r}zJ
e.printStackTrace (); GL-Pir
} Mi<l;ZP
*v#Z/RrrA
=))VxuoN
return n; Yln[ZmK9g
} duV\Kt/g^
LV8{c!"
P$v9
} :>-&
pGcijD
m%%\k \
/* kYZj^tR
**SiteInfoBean.java E?(:9#02
*/ )mu[ye"p
package NetFox; LMRq.wxbbB
.#{m1mr
,zOv-pH
public class SiteInfoBean { YP`/dX"4
#k t+ )>
"R0(!3
private String sSiteURL; //Site's URL ]$)U~)T iW
private String sFilePath; //Saved File's Path bL2b^UB~%
private String sFileName; //Saved File's Name H`OJN.
private int nSplitter; //Count of Splited Downloading File Ey&gZ$|&
hQ}y(2A.XI
{JtfEna
public SiteInfoBean() A5^tus/y
{//nSplitter的缺省值为5 ~=t K17i
//default value of nSplitter is 5 zU2Mno
this("","","",5); @n;$Edza/
} jJ3dZ<#
u}|+p+
B*otquz
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) aucG|}B
{ 5@^['S4%8*
sSiteURL= sURL; J3y4D}
sFilePath = sPath; ;:aCZ8e
sFileName = sName; [!YSW'
this.nSplitter = nSpiltter; ^]TYS]C
f,VJfY?#
UF;iw
} 2`pg0ciX (
[&+5E1%L
J_d!` Hhe
public String getSSiteURL() "$U!1
{ HME`7dw?
return sSiteURL; C!^[d
} #T08H,W/
.-}F~FES
7;SI=
public void setSSiteURL(String value) /^':5"=o
{ >?(}F':
sSiteURL = value; 6XI$ o,{
} u.,l_D_
b$N&sZ
3>%:%bP
public String getSFilePath() ]::g-&%Um
{ OFn#C!
return sFilePath; &5Huv?^a'
} Qn`Fq,uvL
2!";?E
;fZ9:WB
public void setSFilePath(String value) c3C<P
{ aUbmEHFTV
sFilePath = value; ~ ":}Rs
} />dYkIv
BL H~`N3U
c. 06Sw*
public String getSFileName() 6HRr4NDcj
{ f~w!Z
return sFileName; b9TsuY
} -HUlB|Q8r
A3Oe=rB
0%"sOth
public void setSFileName(String value) eY8rm
{ [)t1"
sFileName = value; M7\yEi"*
} Q$8K-5U%
OpFm:j3
h4tAaPcS+
public int getNSplitter() FwqaWEk
{ !Hx[ `3
return nSplitter; ,O`~ D~$
} PiF&0;
.?)gn]#
6Ej.X)~'K
public void setNSplitter(int nCount) C(}N*e1
{ h+j{;evN
nSplitter = nCount; !M;><b}=5
} m.w.h^f$&
} UQ}#=[)2e
VQ^}f/A
}N0v_Nas;v
/* /<Yz;\:Jy
**Utility.java D"8?4+
*/ 9}jezLI/3
package NetFox; pFcCe 'd"
]La~Bh6;m
Qz`v0"'w
public class Utility { _ls i,kg?
%JPBD]&M
]?lUe5F
public Utility() % 9} ?*U
{ fzZ`O{$8
8C8,Q\WV(~
s5J?,xu
} 36UUt!}p
1UkGjw1J
//线程睡眠 IIO-Jr
public static void sleep(int nSecond) a~&euT2
{ v/x~L$[
try{ u#nM_UJe
Thread.sleep(nSecond); /q5!p0fH*
} )Y:C'*.r
catch(Exception e) og`K!d~
{ h?P- :E
e.printStackTrace (); $LW8 vo7
} {'z(
} 1<;G oC"
.O6(QI*
//日志 <Wm'V-
public static void log(String sMsg) #j4RX:T*[
{ `Ha<t.v(
System.err.println(sMsg); ne 8rF.D
} <op|yh3Jkk
dO4Jf9)
gN.n_!
public static void log(int sMsg) /a}` y
{ -8Hv3J'=
System.err.println(sMsg); J*4T|#0
} e[Jh7r>'
} ){4!
GTke<R
yq12"Rs
/* }U@(S>,%
**TestMethod.java /kAbGjp0
*/ <Yn-sH
package NetFox; H1r8n$h
rA /T>ZM
YI?tmqzt
public class TestMethod { ,"5][RsOn
7)*q@
rmeGk&*R8
public TestMethod() `JcWH_[
{ ///xx/weblogic60b2_win.exe g}$B4_sY
try{ 3;F up4!4}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ZG(Pz9{K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); BG/RNem
SiteFileFetch fileFetch = new SiteFileFetch(bean); NIG* }[}P
fileFetch.start(); K"8!
} bMGXx>x
catch(Exception e){e.printStackTrace ();} Y%^qt]u.8
+S@[1 N
Ge1"+:tbJ
} PAXm
KM/c^a4V
j%i6H1#.Z
public static void main(String[] args) pYh\l.@qf
{ 4VhKV JX
new TestMethod(); VjJ}q*/3e
} bzh:
} @PV3G KJ
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