http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); Gq0]m
} @@%i(>4Z
for(int i=0;i<nEndPos.length-1;i++) 83 i1
{ `sk!C7%
nEndPos = nStartPos[i+1]; q6C6PPc
} tIGVB+g{F
nEndPos[nEndPos.length-1] = nFileLength; w\o)bn
} + %MO7vL
} d`9W
pwFU2}I
c?!YFm
//启动子线程 /lS+J(I
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kfqpI
for(int i=0;i<nStartPos.length;i++) RHwaJ;:)#
{ =mHkXHE~:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yHWi[7$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KMK&[E#r
nStartPos,nEndPos,i); I #M%%5e
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "K|)<6J
fileSplitterFetch.start(); @,x_i8
} 861i3OXVE>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gh]_L+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); hncS_ZA
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Y8)E]D
nEndPos = " + nFileLength); p~Hvl3SxR
// fileSplitterFetch[nPos.length-1].start(); 4AY _#f5u
N+CXOI=6x
NI5]Nz<?
//等待子线程结束 >H0) ph
//int count = 0; ^w:OS5%R
//是否结束while循环 0W T#6D
boolean breakWhile = false; 5:Yck<
c Ndw9?Z
.7 (DxN
while(!bStop) j>0<#SYBu
{ ?w+ QbT
write_nPos(); QP6z?j.
Utility.sleep(500); ?YqJ.F;
breakWhile = true; w`c0a&7
r-RCe3%g%
w=f0*$ue+w
for(int i=0;i<nStartPos.length;i++) NXzU0
{ tmO;:n<N
if(!fileSplitterFetch.bDownOver) )Qh>0T+(
{ "El^38Ho
breakWhile = false; G1kaF/`O
break; v!NB~"LQ
} .MDYGWKt
} *0%4l_i
if(breakWhile) AIuMX4nb
break; -"W)|oC_
5cD XWF
h [nH<m
//count++; 1s#yWQ
//if(count>4) n,t6v5>88
// siteStop(); 9o-!ecx}
} kWB, ;7
Gs[Vu@*
cCM j\H@
System.err.println("文件下载结束！"); UdT&cG
} /Zo~1q
catch(Exception e){e.printStackTrace ();} P3'2IzNw
} W8f`J2^"M
BJ~ivT<
puFXPw.3
//获得文件长度 +$>N]1
public long getFileSize() \,>_c
{ ?VFM]hO
int nFileLength = -1; DdBxqkh
try{ n!GWqle
URL url = new URL(siteInfoBean.getSSiteURL()); 8@E8!w&~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TE3*ktB{N
httpConnection.setRequestProperty("User-Agent","NetFox"); (# JMB)
rmOQ{2}
h^}_YaT\
int responseCode=httpConnection.getResponseCode(); l iw,O 6
if(responseCode>=400) }o-|8P:Y
{ `vudS?
processErrorCode(responseCode); +'-rTi\
return -2; //-2 represent access is error "Dyym<J
} @ru<4`h
|2z}Xm5\
jvu N
String sHeader; xN6>2e
A2Q[%A
M]c7D`%s
for(int i=1;;i++) CE)*qFs
{ :`D'jF^S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); QQ@9_[N
//Utility.log(in.readLine()); 5v"Y\k+1
sHeader=httpConnection.getHeaderFieldKey(i); _-n Y2)
if(sHeader!=null) Z;hyi'rPJ
{ A:/}`
if(sHeader.equals("Content-Length")) hQXxG/yFm
{ P3G:th@j=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); aSUsyOe
break; l1&5uwuF
} =M/qV
} +Y7Pg'35
else M~-h-tG
break; V|TA:&:7
} L#n}e7Y9
} H ZPcd_(
catch(IOException e){e.printStackTrace ();} hHpx?9O+!
catch(Exception e){e.printStackTrace ();} GE@uOJ6H
im=5{PbJ^
/mc*Hc8R8
Utility.log(nFileLength); @8|Gh]\P
]GNh)
I-,>DLG
return nFileLength; i<mevL
} 3c b[RQf
=nzFd-P
[eyb7\#
//保存下载信息（文件指针位置） V"O9n[|
private void write_nPos() H"_v+N5=
{ HL@TcfOe~
try{ ~x'zX-@rC
output = new DataOutputStream(new FileOutputStream(tmpFile)); VUp. j
output.writeInt(nStartPos.length); +$PFHXB
for(int i=0;i<nStartPos.length;i++) wS V@=)H\:
{ l8^y]M
// output.writeLong(nPos); r&SO:#rOSM
output.writeLong(fileSplitterFetch.nStartPos); I:F <vE
output.writeLong(fileSplitterFetch.nEndPos); SZ/(\kQ6
} \*uugw,\y
output.close(); bhYU5I 9
} ha5e(Hj?
catch(IOException e){e.printStackTrace ();} glx2I_y
catch(Exception e){e.printStackTrace ();} ]oEQ4
} AuAT]`
;Z*'D}
(-\]A|
//读取保存的下载信息（文件指针位置） /l^y}o %?
private void read_nPos() `NQ{)N0!
{ ijFV<P
try{ 'j}g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ehE-SrkU'
int nCount = input.readInt(); -,^WaB7u\
nStartPos = new long[nCount]; :W~f;k
nEndPos = new long[nCount]; U+} y %3l
for(int i=0;i<nStartPos.length;i++) ;|!MI'Af
{ >b>gr OX
nStartPos = input.readLong(); UT4f (Xo
nEndPos = input.readLong(); P{cos&X|
} bEd?^h
input.close(); zks#EzQ
} J?IC~5*2
catch(IOException e){e.printStackTrace ();} N!L'W\H,
catch(Exception e){e.printStackTrace ();} F$h'p4$T
} ds]?;l"
-D#5o,]3
T%kKVr
private void processErrorCode(int nErrorCode) dQ<(lzS~
{ g5}lLKT
System.err.println("Error Code : " + nErrorCode); ]YsR E>
} T`?n,'!(
@^!\d#/M
xQo~%wW,?
//停止文件下载 _IxamWpX$
public void siteStop() 4[1k\
{ '00J~j~
bStop = true; #/+I*B*y
for(int i=0;i<nStartPos.length;i++) IcFK,y%1
fileSplitterFetch.splitterStop(); f>niFPW"
^wJEfac
)|RZa|`-G
} p![&8i@ym
} vU}: U)S
//负责部分文件的抓取 s`c?:
**FileSplitterFetch.java j=W@P-
*/ Vv7PCaq
package NetFox; Xhse~=qA
P>wZ~Hjk
({e7U17[#
import java.io.*; 2:'lZQ
import java.net.*; (@q3^)I4
)[jy[[K(
)~}PgbZ^
public class FileSplitterFetch extends Thread { +9zA^0
nLJBq)i
~C|,b"
String sURL; //File URL E0YU[([G
long nStartPos; //File Snippet Start Position u s`}
long nEndPos; //File Snippet End Position @6b[GekZ<
int nThreadID; //Thread's ID HN68!v}C|
boolean bDownOver = false; //Downing is over cy3M^_5B<
boolean bStop = false; //Stop identical fK_~lGY(
FileAccessI fileAccessI = null; //File Access interface hgO?+x
6m+W#]^
"0-y*1/m
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException lR@& Z6lw
{ W2<3C
this.sURL = sURL; ! =WcF5
this.nStartPos = nStart; H)5QqZ8
this.nEndPos = nEnd; ,QvYTJ{
nThreadID = id; F7T E|LZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 TatMf;?h&
} KO&:06V{
H&bh<KPMh
7/"@yVBW
public void run() 6m[9b*s7
{ P}@*Z>j:#
while(nStartPos < nEndPos && !bStop) d}-'<Z#G
{ -:SIS`0s
jDTUXwx7V
S+ebO/$>
try{ "w&/m}E,[
URL url = new URL(sURL); M&yqfb[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S}cF0B1E*
httpConnection.setRequestProperty("User-Agent","NetFox"); GNU;jSh5
String sProperty = "bytes="+nStartPos+"-"; s;1e0n
httpConnection.setRequestProperty("RANGE",sProperty); z0Xa_w=
Utility.log(sProperty); |>2:eH
CH;;V3
_~A~+S}
InputStream input = httpConnection.getInputStream(); DYRE1!
//logResponseHead(httpConnection); A1-qtAO]
_z8;lt
0d4cE10
byte[] b = new byte[1024]; %v4ZGtKC@
int nRead; Tpzw=bC^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Rd%0\ B
{ 31}W6l88c
nStartPos += fileAccessI.write(b,0,nRead); 9j#@p
//if(nThreadID == 1) &{W^W8,%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WZ?!!
} bulboyA&#
FH*RU1Z
z-@-O
Utility.log("Thread " + nThreadID + " is over!"); 2xTT)9Tq*
bDownOver = true; ?@UAL.y
//nPos = fileAccessI.write (b,0,nRead); GMm'of#
} A5XR3$5P
catch(Exception e){e.printStackTrace ();} r1Z<:}ZwK
} r)b<{u=]
} 54q3R`y
8=Q VN_
Y6ben7j%-
//打印回应的头信息 wiE]z
public void logResponseHead(HttpURLConnection con) yd>}wHt
{ ?/d!R]3
for(int i=1;;i++) wL2XNdo}<
{ &Rp"rMeW
String header=con.getHeaderFieldKey(i); -t4 [oB
if(header!=null) 1TRN~#ix
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [/ohk&
Utility.log(header+" : "+con.getHeaderField(header)); *48IF33&s
else SRCOs1(EK9
break; %&<W(|U1<
} a)9rs\Is{
} 16$y`~c-z
&p"(-
3hS6jS
public void splitterStop() l h/&__
{ 0{R/<N
bStop = true; I/B1qw;MN
} xK;e\^v
"^%Z'ou
(p |DcA]BX
} h\y-L~2E
ut5yf$%
BXhWTGiG
/* s;{K!L@
**FileAccess.java U CY2]E
*//文件访问(定位，写) )#`H."Z
package NetFox; AyTx'u
import java.io.*; m;/i<:`
NHiq^ojk
<4mQ*6
public class FileAccessI implements Serializable{ tt4+m>/T
}.{}A(^YR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Nl*i5 io
RandomAccessFile oSavedFile; &U&%ka<*
long nPos; _/ Os^>R
]}2Ztr)zZ
9Nt3Z>d
public FileAccessI() throws IOException \9/1L?@
{ /cY^]VLe
this("",0); ($WE=biZ&
} qY# d+F,t
nb+m.X
OD+5q(!"a
public FileAccessI(String sName,long nPos) throws IOException P(h5=0`*PR
{ 2p:r`THvS5
oSavedFile = new RandomAccessFile(sName,"rw"); ;V.vfar
this.nPos = nPos; r4;Bu<PQN1
oSavedFile.seek(nPos); 6^YJ]w
} & _K*kI:
]d'^Xs
K/Y Agg
public synchronized int write(byte[] b,int nStart,int nLen) BUC,M:J+H
{ Q$=*aUU%G
int n = -1; }<[Db}?9
try{ +LzovC@^
oSavedFile.write(b,nStart,nLen); HDS"F.l5
n = nLen; \*"`L3
} km\%BD~
catch(IOException e) nNn56&N]
{ -(;LQDG |
e.printStackTrace (); /EFq#+6
} @@}`hii
59!)j>f
fLB1)kTS
return n; 77We;a
} UR3$B%i
Alz~-hqQ
`Q%NSU?
} |E|6=%^
SS8ocGX
3"rkko?A
/* Lk.h.ST
**SiteInfoBean.java F?4Sz#
*/ *fhX*e8y
package NetFox; B\_[R'Pf&
FH\CK
cY{Nos
public class SiteInfoBean { JTUNb'#RZ
lrys3
Tbh'_F6
private String sSiteURL; //Site's URL nj2gs,k
private String sFilePath; //Saved File's Path h>3H7n.
private String sFileName; //Saved File's Name R6@uM<
private int nSplitter; //Count of Splited Downloading File ^:DyT@hQB5
N@1p]\
SrZ50Se
public SiteInfoBean() 6?SFNDQ"C
{//nSplitter的缺省值为5 g6euXI
//default value of nSplitter is 5 v0 ];W|
this("","","",5); oI@9}*
} s~$zWx@v
=`p&h}h-L
l$XA5#k
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hC>wFC
{ - ]Y wl
sSiteURL= sURL; 6k9LxC:M
sFilePath = sPath; qrDcL>Hrn
sFileName = sName; T[2}p=<%
this.nSplitter = nSpiltter; 3j*'HST
sh6(z?KP
=_QkH!vI
} .~`Y)PON
!F7:i
)N)ljA3]
public String getSSiteURL() rYGRz#:~+
{ hKksVi
return sSiteURL; g42T#p8^
} 4vqNule
WK;(P4Z
)iSy@*nY
public void setSSiteURL(String value) \dV Too
{ &jm[4'$ *z
sSiteURL = value; sv=H~wce
} n\ Uh
D#v?gPo4
oVkr3KZ
public String getSFilePath() p>p'.#M
{ gpAHC
return sFilePath; s*JE)
} 3qo e^e
k18$JyaG
e&3#2_
public void setSFilePath(String value) *Nlu5(z
{ O5;-Om
sFilePath = value; o!Fl]3F
} H#+xKYrp
@HEPc95
ou6j*eSN
public String getSFileName() a:u}d7T3e
{ ]u=Ca#!'
return sFileName; j9xXKa5
} lzfDH=&
ORH93`
oT->^4WY
public void setSFileName(String value) ^saM$e^c:
{ \!wh[qEQ\
sFileName = value; `Bu9Nq
} D5`(}
b1=pO]3u
S=O$JP79
public int getNSplitter() Wz{%"o
{ !K\itOEP-
return nSplitter; 8c).8RLf
} mP!N<K
evOb
7@P656{
public void setNSplitter(int nCount) RpN <=
{ Qa?aL
nSplitter = nCount; uF<S
} b *9-}g:
} `a'`$'j
a#QByP
}+DDJ6Jzs
/* C1 {ZW~"YI
**Utility.java +*a7GttU
*/ IJIQ" s
package NetFox; S'@=3)
ND*]gM
BD'NuI
public class Utility { hbnS~sva
>zR14VO`_|
CB]l[hM$
public Utility() .. UoyBV
{ ]xrD<
CB({Rn
%uuH^A
} cY~M4:vgT
4\1;A`2%0
//线程睡眠 YFqZe6g0$
public static void sleep(int nSecond) :gaETr
{ o^PuhVu
try{ bK7.St
Thread.sleep(nSecond); 9K$]h2
} p1^0{ILx
catch(Exception e) lh$CWsx
{ @+t (xCv
e.printStackTrace (); i;]CL[#2e`
} {Zwf..,
} B^m!t7/,
M[z3 f
//日志 xgs@gw7!n0
public static void log(String sMsg) yjd(UWE
{ YZ\@)D;
System.err.println(sMsg); GBr,LN
} <Wf0QO,
)JX$/- RD-
hr1$1&p
public static void log(int sMsg) .qinR6=
{ 9A<0zt
System.err.println(sMsg); mt^`1ekoY
} \!4|tBKVY
} cD8Ea(
@T/qd>T o
GEfY^!F+
/* U2UyN9:6F
**TestMethod.java :iEAUM
*/ P'F~\**5
package NetFox; g8v[)o(qd
P4[]qbfd,
@it/$>R^)
public class TestMethod { yU!GS-
{\Ys@FF
@E(P9zQ/zy
public TestMethod() V" }*"P-%
{ ///xx/weblogic60b2_win.exe _<2RYXBC
try{ }Az'Zu4 =
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F-tFet
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dm 2EH
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9.]kOs_
fileFetch.start(); `fMpV8vv
} ()B7(Y
catch(Exception e){e.printStackTrace ();} 9R>~~~{-Go
r},lu=em
!"%S#nrL$
} vlAy!:CV
`Jqf**t
F;W'
public static void main(String[] args) aPt{C3<
{ N5ci};?
new TestMethod(); a_AJ)4
} u]SZ{[e
} EO"6Dq(
点击下载更多相关资料