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)); <#wVQ\0C
} R$p(5>#\5
for(int i=0;i<nEndPos.length-1;i++) DheQcM
{ 6RG63+G
nEndPos = nStartPos[i+1]; ,^7]F"5
} VsJKxa4
nEndPos[nEndPos.length-1] = nFileLength; FJ{/EloF
} &2Ef:RZF
} wPX^P
O^PN{u
_e/Bg~
//启动子线程 CpB,L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YG /@=Z.
for(int i=0;i<nStartPos.length;i++) n.i8?:
{ .SLpgYFL{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (xE |T f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /M JI^\CA
nStartPos,nEndPos,i); /~Bs5f.]?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MsZx 0]
fileSplitterFetch.start(); $o0.oY#
} IT7],pM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FUf.3@}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9)8Cf%<(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &6vWz6!P
nEndPos = " + nFileLength); +$Y*1{hyOo
// fileSplitterFetch[nPos.length-1].start(); h$}PQ
B&7NF}CF2
dVk(R9 8
//等待子线程结束 QJ(5o7Tfn
//int count = 0; f5p/cUzX
//是否结束while循环 61b*uoq0w?
boolean breakWhile = false; MsBm0r`a
U{j4FlB
D.-G!0!
while(!bStop) >28l9U
{ "h #/b}/
write_nPos(); ?"^{:~\N
Utility.sleep(500); lSBR(a<\y
breakWhile = true; p_ f<@WE
9^9-\DG
(@qPyM6~}
for(int i=0;i<nStartPos.length;i++) Y mL{uV$
{ zVa&4 T-
if(!fileSplitterFetch.bDownOver) ,q>cFsY=i?
{ `GkCOx,
breakWhile = false; a#{"3Z2|
break; :b*7TJ\grN
} :|$cG~'J
} V2|By,.
if(breakWhile) {F2Rv
break; e&2,cQRFV
Te[v+jgLY,
W/%hS)75
//count++; [& Z- *a
//if(count>4) 1r};cY6
// siteStop(); @?3^Ks_
} fm@Pa} ,
_5H~1G%q
(~%NRH<\
System.err.println("文件下载结束！"); [u$|/
} i39ZBs@
catch(Exception e){e.printStackTrace ();} <i4]qO(0u
} 6%h%h: e
Ov<c1y;f
'l=>H#}<B
//获得文件长度 $8i`h}AM
public long getFileSize() Z'>UR.g
{ ;HH%OfQq
int nFileLength = -1; G<=I\T'g;
try{ Y<u%J#'[
URL url = new URL(siteInfoBean.getSSiteURL()); p"c6d'qe
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k*n~&y:O
httpConnection.setRequestProperty("User-Agent","NetFox"); u z7|!G!43
6dmb bgO)
b_ak@LYiu
int responseCode=httpConnection.getResponseCode(); UWEegFq*
if(responseCode>=400) U65l o[
{ :IBP "
processErrorCode(responseCode); \O4s0*gw
return -2; //-2 represent access is error ]hS<"=oj
} w|]Tt="
*;9H\%
vanV|O
String sHeader; [5p3:D
l"(PP3
Gp \-AwE
for(int i=1;;i++) \Cu=Le^
{ k(pJVez
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1;1;-4k7I
//Utility.log(in.readLine()); YJMs9X~3
sHeader=httpConnection.getHeaderFieldKey(i); l"A/6r!Dp
if(sHeader!=null) Exqz$'(W9
{ 7%EIn9P
if(sHeader.equals("Content-Length")) wM4{\ f\
{ qqe"hruFJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .B-b51Uz
break; $u.rO7)
} Z^2SG_pD
} x?V^l*
else 3vcyes-U
break; Pg8boN]}
} OblHN*
} ;l_b.z0^6
catch(IOException e){e.printStackTrace ();} 6WQN!H8+^
catch(Exception e){e.printStackTrace ();} =oIt.`rf
?g{[U0)
\XmplG:
Utility.log(nFileLength); k kAg17 ^
{q`8+$Z;
>n3GvZ5%
return nFileLength; &gruYZGK
} V\x'w*FP
2,q*8=?{6P
?k4Hk$V
//保存下载信息（文件指针位置） dp^PiyL
private void write_nPos() \fEG5/s}T
{ D{Nd2G
try{ nvf5a-C+q
output = new DataOutputStream(new FileOutputStream(tmpFile)); mjP
output.writeInt(nStartPos.length); |Vqm1.1/Zv
for(int i=0;i<nStartPos.length;i++) zHz>Gc
{ &WBpd}|+Y
// output.writeLong(nPos); 2<5LQr
output.writeLong(fileSplitterFetch.nStartPos); )L6 it
output.writeLong(fileSplitterFetch.nEndPos); ..E_M$}
} 9ybR+dGm+
output.close(); M j[+h|e
} ;Us6:}s
catch(IOException e){e.printStackTrace ();} "lu^
catch(Exception e){e.printStackTrace ();} Bo8f52|
} Z(tJd,
0.wF2!V.
D((/fT)eD
//读取保存的下载信息（文件指针位置） 6Aqv*<1=62
private void read_nPos() -XL?n/M
{ =23B9WT
try{ KTT!P 4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); BM:p)%Pv#P
int nCount = input.readInt(); d*Su c
nStartPos = new long[nCount]; /nA>ox78
nEndPos = new long[nCount]; AZhI~QWo
for(int i=0;i<nStartPos.length;i++) {'A 15
{ yN{**?b
nStartPos = input.readLong(); jZqa+nG51
nEndPos = input.readLong(); [dP<A?s
} ]~dB|WB
input.close(); ,&4 [`d
} 8A]8yX =
catch(IOException e){e.printStackTrace ();} hz;SDaBA
catch(Exception e){e.printStackTrace ();} Od;k}u6;<
} @w==*.x
#e-7LmO~
paD[4L?4Hk
private void processErrorCode(int nErrorCode) OfBWf6b
{ aC1 xt(
System.err.println("Error Code : " + nErrorCode); <:/aiX8
} v"(6rZsa
#S/~1{
hlV(jz
//停止文件下载 /G7^l>pa
public void siteStop() ,Aq, f$5V
{ c/bT5TIEWs
bStop = true; 6Zw$F3 <
for(int i=0;i<nStartPos.length;i++) u;^H=7R
fileSplitterFetch.splitterStop(); [= E=H*j
}])j>E
[7`S`\_NK
} Pfvb?Hy
} uv$5MwKU
//负责部分文件的抓取 M^WoV }'
**FileSplitterFetch.java |n,O!29
*/ u"v$[8
package NetFox; "[["naa
9mMQ
B &Z0ZWx
import java.io.*; =r]_$r%gR
import java.net.*; oSMIWwg7G
F'{T[MA
ZT&[:>upR
public class FileSplitterFetch extends Thread { Uhh[le2 %
j^8Hjg
7SkW!5
String sURL; //File URL N/{=j
long nStartPos; //File Snippet Start Position MJe/ \
long nEndPos; //File Snippet End Position ?cz7s28a
int nThreadID; //Thread's ID rS\mFt X
boolean bDownOver = false; //Downing is over 8sDw:wTC
boolean bStop = false; //Stop identical :+_H%4+
FileAccessI fileAccessI = null; //File Access interface Z] cFbl\ma
M-QQ
b9.7j!W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException epk C'
{ 8[^b8^
this.sURL = sURL; E]a,2{&8<
this.nStartPos = nStart; j yp.2c
this.nEndPos = nEnd; DP*V|)
nThreadID = id; r H9}VA:h
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T^|6{ S\
} iuEe#B;!
gEVoY,}/-U
k~<ORnda
public void run() 5 YIk
{ <Vyl*a{%
while(nStartPos < nEndPos && !bStop) /*S6/#
{ p0Ij4
'#lEUlB
t2.]v><
try{ GZ:1bV37%
URL url = new URL(sURL); M#],#o*G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [e.`M{(TB
httpConnection.setRequestProperty("User-Agent","NetFox"); y>UQm|o<W
String sProperty = "bytes="+nStartPos+"-"; /WAOpf5
httpConnection.setRequestProperty("RANGE",sProperty); W-RshZ\
Utility.log(sProperty); %I)*5M6
+Sv2'& B
Sf`?j
InputStream input = httpConnection.getInputStream(); ]Ah<kq2sk
//logResponseHead(httpConnection); &s.-p_4w^D
0[Zs8oRiI
"\afIYS I
byte[] b = new byte[1024]; J(,gLl
int nRead; QA!'p1{#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M|z4Dy
{ bq5?fPBrq
nStartPos += fileAccessI.write(b,0,nRead); x*^)B~7}
//if(nThreadID == 1) ir)~T0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Vc|QW
} Mm"0Ip2"
+{e2TY
G"<} s mB
Utility.log("Thread " + nThreadID + " is over!"); ~|wh/]{b9
bDownOver = true; Xdf;'|HO
//nPos = fileAccessI.write (b,0,nRead); %8%0l*n'
} _32 o7}!x
catch(Exception e){e.printStackTrace ();} !| GD8i
} =WFG[~8
} #)%dG3)e
+N:M;uTS
)!`>Q|]}Zd
//打印回应的头信息 /EM=!@ka
public void logResponseHead(HttpURLConnection con) 5=_))v<Tp
{ 'khhn6itA
for(int i=1;;i++) ? i|LO
{ 5m6I:s`pK
String header=con.getHeaderFieldKey(i); RjR
if(header!=null) r<kqs,-~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7LW%:0
Utility.log(header+" : "+con.getHeaderField(header)); _vE[TFy
else ~{yQsEU
break; "g;}B"rG
} za4:Jdr
} V@ph.)z
=G/`r!r*0I
H 4W4#\M
public void splitterStop() n<7R6)j6
{ QW@`4W0F
bStop = true; 1QuR7p
} -+|{#cz
]M9r<x*
ZEU/6.
} ^5gB?V,
|f&=9%
{B6tGLt#bf
/* `OyYo^+D|.
**FileAccess.java Rwz (20n\^
*//文件访问(定位，写) Q(YQ$i"S
package NetFox; (=i+{ 3`|
import java.io.*; DKf:0E8
OOX}S1lA
Q pbzx/2h
public class FileAccessI implements Serializable{ Wp$'#HhB
3HmJixy
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'St\$X
RandomAccessFile oSavedFile; m&r?z%
long nPos; [mI;>q
M)CE%/P
|/35c0IM
public FileAccessI() throws IOException y 4jelg
{ SA16Ng
this("",0); uzUZuJ
} GSu&Z/Jo
s3l:ST
2l!* o7
public FileAccessI(String sName,long nPos) throws IOException zINziAp{
{ {B lM<
oSavedFile = new RandomAccessFile(sName,"rw"); G^Yg[*bJ^$
this.nPos = nPos; &ffd#2f`@
oSavedFile.seek(nPos); q--;5"=S
} >NN&j#;x~
r$Ck:Q}
}xM >F%
public synchronized int write(byte[] b,int nStart,int nLen) p8MPn>h<
{ 4ky@rcD1
int n = -1; 2f$6}m'Ad
try{ </8F
oSavedFile.write(b,nStart,nLen); J'>i3eLq
n = nLen; :vJ0Ypz-u
} (>Tq
catch(IOException e) g!`$bF=e
{ T"$yh2tSY
e.printStackTrace (); m2"~.iM8
} nXOJ
${F]N }
/!Ng"^.e
return n; %7~~*_G
} I=I'O?w
!*C9NX
<);Nc1
} $R[ggH&
AR-&c 3o
AGxG*KuZ
/* #2023Zo]
**SiteInfoBean.java wfxg@<WR
*/ Z>H y+Q4
package NetFox; \{ui{8+G
nZ 0rxx[V?
U&\8~h
public class SiteInfoBean { <X_I`
3o=K?eOdg
;:l\_b'Z}
private String sSiteURL; //Site's URL >~sAa+Oxi
private String sFilePath; //Saved File's Path >)3[CU,
private String sFileName; //Saved File's Name ,1+)qv#|i
private int nSplitter; //Count of Splited Downloading File $fwv'
2%Y]M%P
AI&Bv
public SiteInfoBean() T~rPpi&
{//nSplitter的缺省值为5 `'{>2d%\g
//default value of nSplitter is 5 Q,mmHw.`J
this("","","",5); q^_PR|
} v}$KlT
p=65L
}qf)L.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .*s1d)\:
{ dt(#|8i%
sSiteURL= sURL; Rx22W:S=C.
sFilePath = sPath; Ok=RhoZZ
sFileName = sName; CN$wlhs
this.nSplitter = nSpiltter; ljij/C=
DhwFD8tT
RTW4r9~'
} :!h1S`wS
^Z{W1uYi
A@X&dy
public String getSSiteURL() .*N,x0B(
{ E K)7g~
return sSiteURL; VE<&0d<
} m\88Etl@
o#-K,|-
+d0&(b
public void setSSiteURL(String value) \WnI&nu
{ J<<0U;
sSiteURL = value; <= xmJx-V
} +|N!(H
>+w(%;i;
,3t('SE
public String getSFilePath() 8()L}@y
{ 8T:|~%Sw
return sFilePath; n\#RI9#\
} \/J7U|@Lt
yE(>R(^
a+TlZE>8
public void setSFilePath(String value) q89#Ftkt
{ ztNm,1pnQ
sFilePath = value; `43`*=
} 8Q&hhmOnz
wr/Z)e =^3
][|)qQ%V
public String getSFileName() meHAa`
{ ]E1aIt
return sFileName; Qo!/]\
} CF`tNA3fxm
ik@g;>pQD
MVW2%6
public void setSFileName(String value) 7T]}<aK<c[
{ dsKEWZ =
sFileName = value; z:hY{/-
} ZqHh$QBD 9
.D^=vuxt~
7(m4,l+(
public int getNSplitter() *<yKT$(+_
{ QfuKpcT&
return nSplitter; d~](S<k
} ^FJ=/#@T
;&Q8xC2
$d4^e&s
public void setNSplitter(int nCount) uP\?y(="
{ }b-"[TDEF
nSplitter = nCount; FqOV/B /z2
} Y|t]bb
} bJJB*$jW=
m L#-U)?F
[-X=lJ:+h
/* }JXAG/<
**Utility.java #%4-zNS
*/ jg]_'^pVzr
package NetFox; [:x^ffs
>5{Z'UWxh
[HJ^'/bB'
public class Utility { >yC1X|d~t
+$KUy>
Np4';H
public Utility() Hmt}@
{ DBuvbq-
KJPCO0"
\$Xo5f<
} 12\h| S~
!Pf_he
//线程睡眠 <0OZ9?,dm
public static void sleep(int nSecond) >=|Dir
{ 6Y^UC2TBs
try{ }Yt/e-Yg%r
Thread.sleep(nSecond); CA7ZoMB#
} hr&&"d {s
catch(Exception e) m}\G.$h4
{ p2N;-
e.printStackTrace (); D[2I_3[wp
} 3fJGJW!zu
} f>k<I[C<
]iewukB4
//日志 isaDIl;L/
public static void log(String sMsg) NIcPjo
{ xS%Z
System.err.println(sMsg); .lVC>UT
} jM8e2z3
lwEJ)Bv
99%oY
public static void log(int sMsg) }5~|h%
{ nUi 4!|r
System.err.println(sMsg); 5[.Dlpa'7
} F-?K]t#
} iUl5yq
$Hcp.J[O
8W$uw~|dw
/* tMxa:h;/x
**TestMethod.java vT)(#0>z
*/ 3n;UXYJ%
package NetFox; hj@< wU
gs)wQgJ[
!|hxr#q=4
public class TestMethod { t\J5np
QiB^U^f
&kKopJH
public TestMethod() 6/^$SWd2
{ ///xx/weblogic60b2_win.exe iaAVGgA9+
try{ gUf-1#g4\`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^vXMX^*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }gQ FWT
SiteFileFetch fileFetch = new SiteFileFetch(bean); Xx_v>Jn!
fileFetch.start(); Y!e
} 0|<ER3xkx
catch(Exception e){e.printStackTrace ();} vzl+0"
tu}AJ
Ws"eF0,'Z
} gBQK
=e'b*KTL,
GxWA=Xp^~G
public static void main(String[] args) W]kh?+SZ
{ Pt~mpRlH
new TestMethod(); r`5[6)+P
} +L_!$"I
} %?K1X^52d
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