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)); XTIu(f|d_;
} y @]8Ep
for(int i=0;i<nEndPos.length-1;i++) DBLA% {05
{ $hyqYp"/;
nEndPos = nStartPos[i+1]; uT'-B7N
} #: dR^zr<
nEndPos[nEndPos.length-1] = nFileLength; C,9)V5!tP2
} B#| Z`mZ
} :Pj W:]
$^!a`Xr
u'#`yTB6b
//启动子线程 uDpf2(>s
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 87&KQ_
for(int i=0;i<nStartPos.length;i++) RI#lI~&)
{ }g%KvYB_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _ .-o%6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), u-8X$aJ
nStartPos,nEndPos,i); )RpqZe/h4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oqm
fileSplitterFetch.start(); L`<T'3G
} `wP/Zp{Hy
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Qx9>,e6+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); HGU?bJ~6o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", iMP*]K-O
nEndPos = " + nFileLength); |LXrGyk^
// fileSplitterFetch[nPos.length-1].start(); Ufm(2`FQ
\[@Q}k[
Y\+(rC27
//等待子线程结束 # q0Ub-
//int count = 0; MLkL.1eGSb
//是否结束while循环 6ctHL<^
boolean breakWhile = false; a7XXhsZ
?/o2#iJx
/%N31
while(!bStop) ws*~$x?7
{ L?Kz P.(t+
write_nPos(); xn%l
Utility.sleep(500); Qx6,>'Qk'
breakWhile = true; }:,o Y<
GI0x>Z+
m_{%tU;N
for(int i=0;i<nStartPos.length;i++) A^}i^
{ R@)'Bs
if(!fileSplitterFetch.bDownOver) hj[+d%YZY"
{ Oz4,Y+[#
breakWhile = false; B[) [fE
break; VEFwqB1l
} bLU^1S8Z
} Q0 uP8I}n
if(breakWhile) 5Z4(J?n
break; icKg7-$N
]7XkijNb
o(Ua",|
//count++; 2<46jJYL'
//if(count>4) >!HfH(is\
// siteStop(); 3s+<
} ~8KF<2c
i6!T`Kau
::3iXk)
System.err.println("文件下载结束！"); Q:-%3)g<<
} Dz"u8 f
catch(Exception e){e.printStackTrace ();} ? 6yF{!F*
} 0)6i~MglY
IGh !d?D
d- Z+fz
//获得文件长度 7- *(a
public long getFileSize() }[=xe(4]D
{ I =tyQ`
int nFileLength = -1; 4~MJ4:
try{ Zq\RNZ}
URL url = new URL(siteInfoBean.getSSiteURL()); 2$j Ot}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1sIy*z
httpConnection.setRequestProperty("User-Agent","NetFox"); QK``tWLIg7
L5-T6CD
$'J6#Vs
int responseCode=httpConnection.getResponseCode(); hJC p0F9O
if(responseCode>=400) L&!g33J&
{ +q`rz
processErrorCode(responseCode); t+W=2w&
return -2; //-2 represent access is error TQOg~lH
} S:2u3th7
`uM0,Z
6)uPM"cO
String sHeader; KG4#BY&^
g~ppPAH
n,Yr!W:h
for(int i=1;;i++) oUKBb&&O
{ ^hl]s?"3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (T%F!2i([U
//Utility.log(in.readLine()); !TV_dKa
sHeader=httpConnection.getHeaderFieldKey(i); ^.Ih,@N6
if(sHeader!=null) niBjq#bJi
{ 9QX~aX
if(sHeader.equals("Content-Length")) y'0dl "Dy\
{ !ho5VAt
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |&0"N[t
break; v3hQv)j)
} St~SiTJU
} T~wZ
else Dh!iY0Lz
break; },Re5W nl
} ^sf[dr;BA
} 3x(MvW30Lg
catch(IOException e){e.printStackTrace ();} =jV%O$Fx
catch(Exception e){e.printStackTrace ();} f'zU^/$rf
xtIehr0{$I
8XH|T^5
Utility.log(nFileLength); Zy!)8<Cgm'
tz0Ttu=xH
n ]6 0
return nFileLength; k8x&aH
} xT=kxyu
eF8aB?&"
z|DA _dG
//保存下载信息（文件指针位置） 8[`^(O#\E
private void write_nPos() +/~\b/
{ ].<sAmL^
try{ #<tWYE
output = new DataOutputStream(new FileOutputStream(tmpFile)); jL7MmR#y5"
output.writeInt(nStartPos.length); S$lmEJ_
for(int i=0;i<nStartPos.length;i++) <igx[2X
{ fw:^Lyn9$
// output.writeLong(nPos); \@}$Wjsl
output.writeLong(fileSplitterFetch.nStartPos); O)RzNfI^`N
output.writeLong(fileSplitterFetch.nEndPos); JV?RgFy
} @aiLGwh
output.close(); rs 1*H
} "k6IV&0 3x
catch(IOException e){e.printStackTrace ();} R26tQbwE
catch(Exception e){e.printStackTrace ();} "$V8y
} &x0TnW"g
?CT^Zegmr
PkCeV]`w
//读取保存的下载信息（文件指针位置） ssr)f8R#,#
private void read_nPos() CI~;B
{ SJ~I r#
try{ =@Nv:1:r
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b~haP.Cl:
int nCount = input.readInt(); /c$Ht
nStartPos = new long[nCount]; _#YHc[Wz
nEndPos = new long[nCount]; q5\LdI2
for(int i=0;i<nStartPos.length;i++) :oj) eS[Y
{ L(1,W<kYg
nStartPos = input.readLong(); kX ,FQG>
nEndPos = input.readLong(); CN$A-sjZ
} ^/d^$
input.close(); ,^+R%7mv
} @Y&9S)xcE
catch(IOException e){e.printStackTrace ();} ad$Qs3)6o
catch(Exception e){e.printStackTrace ();} P15*VPy
} %oCjZ"ke
J_wz'eIb0
oCdOC5
private void processErrorCode(int nErrorCode) _!^FW%
{ DCt:EhC
System.err.println("Error Code : " + nErrorCode); > ^v8N
} u$%#5_k
hPeKQwzC0
|phWK^
//停止文件下载 (Y.$wMB
public void siteStop() uQ%HLL-W/
{ P7x?!71?L
bStop = true; V\M!]Nnxr
for(int i=0;i<nStartPos.length;i++) 'y M:WcN
fileSplitterFetch.splitterStop(); ^Lfn3.M
U_{JM`JY
,^IZ[D>u)
} >'|xQjLl
} >3 .ep},
//负责部分文件的抓取 Tvx8l m'
**FileSplitterFetch.java 33KPo0g7
*/ ?jn6Op
package NetFox; TnU$L3k
gAUQQ
])wMUJWg2
import java.io.*; $}UJs <-F
import java.net.*; PKM$*_LcGI
XsN#<"f;i
]ifHA# z`~
public class FileSplitterFetch extends Thread { IM5^E#-g7
o>A%}YU
4e#K.HU_
String sURL; //File URL zT-"kK
long nStartPos; //File Snippet Start Position vzm4
long nEndPos; //File Snippet End Position Sw( H]
int nThreadID; //Thread's ID XK/@!ud"`
boolean bDownOver = false; //Downing is over rH:X/i;D
boolean bStop = false; //Stop identical G~tOCp="p
FileAccessI fileAccessI = null; //File Access interface &?`&X=Q
/bu<,o
OK J%M]<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g5|\G%dOt
{ 5'-9?-S"
this.sURL = sURL; '*ICGKoT
this.nStartPos = nStart; f-nC+
this.nEndPos = nEnd; tWOze, N
nThreadID = id; RMt vEa
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Lm{ o=v
} :(p rx
\q1%d.\X
2,Dc]oj
public void run() lKwT5ma7
{ JI,hy <3l0
while(nStartPos < nEndPos && !bStop) }3_G|
{ hPpXB:(-0
a4.: i
~JPzjE
try{ }o:sx/=u_
URL url = new URL(sURL); CgKSK0/a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1p<?S}zg@
httpConnection.setRequestProperty("User-Agent","NetFox"); P]x+Q
String sProperty = "bytes="+nStartPos+"-"; .mrRv8>$
httpConnection.setRequestProperty("RANGE",sProperty); gpvj'Ri7V
Utility.log(sProperty); y"-{6{3
o5XUDDi
B[|/wHMsT}
InputStream input = httpConnection.getInputStream(); ]b| @<E7Y
//logResponseHead(httpConnection); 64X#:t+
(3r,PS@Qq@
Df3v"iCq}
byte[] b = new byte[1024]; 6b01xu(A[
int nRead; =F[,-B~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) J5IJy3d
{ j5GZ;d?
nStartPos += fileAccessI.write(b,0,nRead); L^s;kkB
//if(nThreadID == 1) l>?vjy65
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,ToEKId
} +rP<m
F|Ihq^q
"a{f? .X.
Utility.log("Thread " + nThreadID + " is over!"); pdiZ"pe
bDownOver = true; G_mu7w
//nPos = fileAccessI.write (b,0,nRead); tp2 _OQAQ
} L1 VTq9[3
catch(Exception e){e.printStackTrace ();} ]m>MB )9
} &L~rq)r/&
} 'Pu;]sC
0^Cx`xdX:
2Hwf:S'
//打印回应的头信息 rNC3h"i\
public void logResponseHead(HttpURLConnection con) L-$g& -
{ F[Sat;Sll
for(int i=1;;i++) M0 8Y
{ $?{zV$r1
String header=con.getHeaderFieldKey(i); QLG,r^
if(header!=null) lGhUfhk
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;gV8f{X{Z
Utility.log(header+" : "+con.getHeaderField(header)); b;l%1x9r
else vy?YA-
break; HI 61rXNF
} o]U==
} \RO Sd
O9)8a]
]XyJ7esg
public void splitterStop() {rLOAewr
{ B=|sLs`I
bStop = true; IPR396J+-
} Yg.u8{H
R FiR)G ,
r+u\jZ
} =x>k:l~s
+Ti@M1A&
Z5A<TC/:
/* 8 K!a:{
**FileAccess.java N>Y3[G+
*//文件访问(定位，写) B,T.bgp\
package NetFox; v^G5 N)F
import java.io.*; m=V2xoMw6
;7>--_?=
m(Ynl=c
public class FileAccessI implements Serializable{ "(qO}&b>
jN0v<_PJED
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 r1]^#&V;MC
RandomAccessFile oSavedFile; Rw`s O:eZ
long nPos; gEu\X|7'
ps{(UYM=b
>2/zL.O
public FileAccessI() throws IOException {r)M@@[
{ K<tg+(3
this("",0); o++Hdvai
} 7Wu2gky3
DJ^JUVi
3Y8 V?* 1|
public FileAccessI(String sName,long nPos) throws IOException Kw|`y %~
{ RI=B(0A
oSavedFile = new RandomAccessFile(sName,"rw"); {w++)N2sh
this.nPos = nPos; Pt+_0OsR
oSavedFile.seek(nPos); }1wuH
} iVcBD0 q)
( 9l|^w["
j>iM(8`t1
public synchronized int write(byte[] b,int nStart,int nLen) j3><J
{ K0]Wb=v
int n = -1; <PxEl4
try{ ZSNg^)cN
oSavedFile.write(b,nStart,nLen); eu=2a>
n = nLen; ra1hdf0"
} DH%X+r
catch(IOException e) .\ZxwD|
{ OZ6%AUot
e.printStackTrace (); I}X8-WFB
} ]+8,@%="
G r)+O
;/.ZYTD
return n; sIpK@BQ'
} |8B[yr.b
oaHBz_pg
cQny)2k*x
} ulQE{c[
>&R|t_ypw
A{QS+fa/
/* .1@5*xQ5O
**SiteInfoBean.java [o~w>,a
*/ ;3!TOY"j;e
package NetFox; H4N==o
:MVD83?4
8Y9mB#X
public class SiteInfoBean { Z+?j8(:n
4ZIXG,@mZJ
G9 !1Wzs
private String sSiteURL; //Site's URL :X^B1z3X4
private String sFilePath; //Saved File's Path Q|>y2g!
private String sFileName; //Saved File's Name wv<"W@& 9
private int nSplitter; //Count of Splited Downloading File nT>?}/S
a4wh-35/
&^EkM
public SiteInfoBean() >g?,BK@
{//nSplitter的缺省值为5 ()rDM@
//default value of nSplitter is 5 V;m3=k0U
this("","","",5); VbN]z:
} R1nctA:
Na=q(OKN
_]\mh,}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 'D1@+FFU0
{ "x{S3v4Rb5
sSiteURL= sURL; Zy'bX* s|
sFilePath = sPath; Gqs8$[o
sFileName = sName; ':Te#S
this.nSplitter = nSpiltter; MV/JZ;55
|peZ`O^~
(i`DUF'#y
} \^+sgg{
O:#to
kxKBI{L
public String getSSiteURL() {PfE7KH
{ os>|LPv4
return sSiteURL; A81kb
} ua0k)4|
Hi?],5,/
<_NF
public void setSSiteURL(String value) k -SUp8}g
{ `0sa94H1[
sSiteURL = value; 4Ld0AApncy
} -i58FJ`B
@A)gsDt9A
sl)_HA7G
public String getSFilePath() !D1F4v[c=
{ ;1BbRnCr
return sFilePath; a/?gp>M9
} GE"#.J4z
'j}%ec1
A}$A~g5Ap
public void setSFilePath(String value) vHao y
{ 4Jw0m#UN1
sFilePath = value; /P,J);Y
} #j@Su )+
u%&zY97/
JeiW z1t
public String getSFileName() #MI}KmH
{ h8nJ$jg
return sFileName; '*22j ]
} Ua(!:5q?
Z,ag5 w`]L
Zr`:A$
public void setSFileName(String value) W[+E5I
{ iX~V(~v
sFileName = value; VN*^pAzlF
} Y0U:i.)
]{dg"J
3pm;?6i6
public int getNSplitter() qdzc"-gH`
{ _t3n<
return nSplitter; (0^u
} n;4`IK|
7IjFSN>
YwEXTy>0
public void setNSplitter(int nCount) '%kk&&3'
{ 5^[V%4y>
nSplitter = nCount; v dyu=*Y
} %KRAcCa7
} oT.g@kf=H
1[/X$DyaK
`2Vc*R
/* D@&0 P&
**Utility.java e<>(c7bF
*/ *cJ GrLC
package NetFox; .\qZkk}2l
<SOC
b4i=eI8
public class Utility { #%Uk}5;-
G5?Dt-;I
\Ua"gS2L
public Utility() r( :"BQ
{ (?D47^F &
}`M[%]MNc
UVA|(:
} u-yQP@^H
b\F(.8
//线程睡眠 G)M9to
public static void sleep(int nSecond) wSBDJvI
{ kuqf(
try{ rhsSV3iM
Thread.sleep(nSecond); D~G24k6b3
} ;}ileLTl
catch(Exception e) AMGb6enl
{ 3u3(BY{"\F
e.printStackTrace (); `)/G5 fB
} N{ @B@]
} 0Ou`&u
|ffM6W1:
//日志 _p<s!
public static void log(String sMsg) MyXgp>?~T
{ %c*azo.
System.err.println(sMsg); |Qo;=~7
} 5VDqx@(
" +'E
KW]/u
public static void log(int sMsg) +'Ec)7m
{ : 2Ho
System.err.println(sMsg); N=YRYUo
} FY|.eY_7 {
} nb9qVuAGU
DJ2EV^D+P
mp:%k\cF|
/* ,b%T[s7
**TestMethod.java :n4?
*/ ?6P P_QY
package NetFox; QWp,(Mv:r
VImcW;Xa
o}C|N)'
public class TestMethod { DG}} S5
v}q3_m]
Iww.Nd2
public TestMethod() gNY}`'~hr
{ ///xx/weblogic60b2_win.exe p,.+i[V
try{ i Tg?JoE2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `j{q$Y=AG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l8/ tR
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2| $
fileFetch.start(); mf^=tZ
} i/N4uq}'A<
catch(Exception e){e.printStackTrace ();} [4KW64%l
0wU8PZ Nj
$@<qaR{t\
} RsIR}.*
<2Lcy&w_M
Bvj-LT=)
public static void main(String[] args) {%.FIw k
{ f0]8/)
new TestMethod(); _C$JO
} 1bs8fUPB3
} B:Ec(USe
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