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)); #p0vrQ;5f
} a:1-n%&F
for(int i=0;i<nEndPos.length-1;i++) eqYa`h@g^
{ `j@2[XdHu
nEndPos = nStartPos[i+1]; )fv0H&g
} U^[<G6<9]
nEndPos[nEndPos.length-1] = nFileLength; gaVWfG
} e;!si>N
} |6$6Za]:
C}#JvNyQ
/z`LB
//启动子线程 h8Kri}z;M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /qEoiL###
for(int i=0;i<nStartPos.length;i++) zaa>]~g.
{ 9tWu>keu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wfz&:J#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Beqzw0
nStartPos,nEndPos,i); ^ola5wD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +,f|Y6L<
fileSplitterFetch.start(); _5y3<H<?
} c&J,O1){\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C8%q?.nH=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m onqaSF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #zyEN+
nEndPos = " + nFileLength); ^,qi`Tk
// fileSplitterFetch[nPos.length-1].start(); iO~3rWQ
".Luc7
p~6/
//等待子线程结束 }$?xwcPU
//int count = 0; _f8Wa u# "
//是否结束while循环 M<4~ewWJ
boolean breakWhile = false; B;@7
sFuB[ JJ}
tI~.3+F
while(!bStop) }vgeQh-G
{ _?]bd-E
write_nPos(); j|c
Utility.sleep(500); xy5&}_Y
breakWhile = true; wsYvbI!
[W;iR_7T5
hRHqG
for(int i=0;i<nStartPos.length;i++) _8P0iC8Zg#
{ Btp 9v<"
if(!fileSplitterFetch.bDownOver) XvETys@d
{ ).0klwfV
breakWhile = false; )!z<q}i5
break; Fuq ;4UcbL
} LVP2jTz
} e:D8.h+&}
if(breakWhile) +}[M&D
break; <[Oe.0SGu
z3x/Y/X$S
C@1B?OfJ
//count++; N@6+DHt
//if(count>4) .5*5S[
// siteStop(); |mvY=t %
} 1k"<T7K
]wb^5H
c_wvuKa
System.err.println("文件下载结束！"); AtU%S9
} a|S6r-_;s
catch(Exception e){e.printStackTrace ();} AUjZYp
} L8R{W0Zr>!
]t0]fb[J
5,dKha
//获得文件长度 |z1er"zR)
public long getFileSize() %x{jmZ$}
{ ~(aMKB
int nFileLength = -1; qHVZsZ
try{ 69< <pm,m
URL url = new URL(siteInfoBean.getSSiteURL()); gOb"-;Zw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `st3iTLZY
httpConnection.setRequestProperty("User-Agent","NetFox"); (-S\%,hO
u-</G-y
zu/BDyF
int responseCode=httpConnection.getResponseCode(); YOOcHo.F
if(responseCode>=400) zD^*->`p
{ N$ oQK(
processErrorCode(responseCode); uvG'Kx
return -2; //-2 represent access is error Rp^fY_
} qkXnpv
xQUskjv/
6&* z
String sHeader; 'Nkd *
^O6eFD U
G]v BI=
for(int i=1;;i++) S$N!Dj@e;
{ c,j[ix
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); m+|yk.md
//Utility.log(in.readLine()); N=T 0Td
sHeader=httpConnection.getHeaderFieldKey(i); <#nt?Xn
if(sHeader!=null) o[^nmHrM2
{ l"zwH
if(sHeader.equals("Content-Length")) ;SgPF:T>Q
{ -kk0zg &|i
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]Z IreI
break; 8/vGA=
} x$hT+z6DUC
} s3-TBhAv
else O2qy[]km
break; [CG3&J
} 1K#%mV_
} *qZBq&7tb
catch(IOException e){e.printStackTrace ();} t i&!_
catch(Exception e){e.printStackTrace ();} icK$W2<8mg
gb{8SG5ac
}Y"vUl_I2
Utility.log(nFileLength); j=dGNi)R
yGY:EvH^?
"F=ta
return nFileLength; Skg}/Ek
} 2kcDJ{(
(u4'*[o\t
%p:Z(zU
//保存下载信息（文件指针位置） SM8f"H28
private void write_nPos() p`2Q6
{ ]JR2Av
try{ !]3kFWs
output = new DataOutputStream(new FileOutputStream(tmpFile)); a>Wr2gPko
output.writeInt(nStartPos.length); "m%EFWUOl
for(int i=0;i<nStartPos.length;i++) ;i?rd f
{ U7''; w
// output.writeLong(nPos); 9m.MGJbQ_f
output.writeLong(fileSplitterFetch.nStartPos); "l{{H&d
output.writeLong(fileSplitterFetch.nEndPos); O\SH;y,N
} ?bPW*A82{q
output.close(); Wo(m:q(Om
} O!ilTMr
catch(IOException e){e.printStackTrace ();} v\@pZw=x
catch(Exception e){e.printStackTrace ();} ;F_P<b 2
} w^9< I]
^(s(4|
^T*!~K8A
//读取保存的下载信息（文件指针位置） + 9I|Fm
private void read_nPos() R$p(5>#\5
{ 0(>3L:
try{ ,^7]F"5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `-JVz{z
int nCount = input.readInt(); |e<$
nStartPos = new long[nCount]; b!e0pFS;
nEndPos = new long[nCount]; S['cX ~
for(int i=0;i<nStartPos.length;i++) t,n2N13
{ G`;\"9t5h
nStartPos = input.readLong(); rog1
nEndPos = input.readLong(); `v-O 4Pk
} ##%&*vh
input.close(); ;%Px~g
} FQ>kTm`d
catch(IOException e){e.printStackTrace ();} h$}PQ
catch(Exception e){e.printStackTrace ();} _%er,Ed
} f[ 2PAz
A;^ iy]"
oHr0;4Lg6
private void processErrorCode(int nErrorCode) UCXRF
{ XUKlgl!+.
System.err.println("Error Code : " + nErrorCode); as'yYn8
} )&O6d .
mP=[h |a$r
BY&{fWUo
//停止文件下载 rHM^_sYRb
public void siteStop() |N^"?bSt
{ AloL+eN@
bStop = true; x.4z)2MO
for(int i=0;i<nStartPos.length;i++) Zk/ejhy0
fileSplitterFetch.splitterStop(); Hq+QsplG
t|V<K^
j!y9E~Zz
} }*U|^$FEU
} KK5;6b
//负责部分文件的抓取 ; o Y|~
**FileSplitterFetch.java W~2,J4=
*/ 4'=Q:o*w`
package NetFox; o&&`_"18
o[}Dj6e\t
z HvE_-
import java.io.*; FZO&r60$E
import java.net.*; %8D>aS U
.ARM~{q6)@
#HH[D;z
public class FileSplitterFetch extends Thread { qHp2;
.d}yQ#5z
1Ml<>
String sURL; //File URL ?O+.
long nStartPos; //File Snippet Start Position \O4s0*gw
long nEndPos; //File Snippet End Position ~nhO*bs}7{
int nThreadID; //Thread's ID (oR~%2K
boolean bDownOver = false; //Downing is over $~G5s<r
boolean bStop = false; //Stop identical $ZGup"z)
FileAccessI fileAccessI = null; //File Access interface qD4s?j-9
i+qg*o$
xGQP*nZ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &Z[+V)6,,
{ S6(48/
this.sURL = sURL; }~|`h1JF
this.nStartPos = nStart; <Vk}U
this.nEndPos = nEnd; .:f ao'
nThreadID = id; oJ %Nt&q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =oIt.`rf
} )I3E
rP'%f 6
iAQ[;M3p
public void run() fo+s+Q|Y
{ fMFkA(Of^
while(nStartPos < nEndPos && !bStop) :0Jn`Ds4o
{ 'DVn /3?X
~dEo^vJD
XWAIW=.
try{ U`=r.>
URL url = new URL(sURL); 3'kKbrk [
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &! h~UZ
httpConnection.setRequestProperty("User-Agent","NetFox"); BHAFO E
String sProperty = "bytes="+nStartPos+"-"; APF`b
httpConnection.setRequestProperty("RANGE",sProperty); rhQ+ylt8I
Utility.log(sProperty); J.:
C(v'7H{4cW
~y"R{-%uS
InputStream input = httpConnection.getInputStream(); eA2*}"W
//logResponseHead(httpConnection); Uz,P^\8^$
Ncbe{}<md
5I6?gv/
byte[] b = new byte[1024]; ,"`3N2!Y}
int nRead; 9ThsR&h3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %A~. NNbS
{ _ps4-<ugC
nStartPos += fileAccessI.write(b,0,nRead); g]HxPq+O
//if(nThreadID == 1) K/C}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); paD[4L?4Hk
} 9NVtvBA
lshSRir
rwUhNth-Qh
Utility.log("Thread " + nThreadID + " is over!"); 85io%>&0
bDownOver = true; P;25F
//nPos = fileAccessI.write (b,0,nRead); W`_Wi*z4
} I:=!,4S;
catch(Exception e){e.printStackTrace ();} bt=D<YZk
} $<Gt^3e
} M_E$w$l2<
&f'Lll
~P,Z@|c4
//打印回应的头信息 : ciwh
public void logResponseHead(HttpURLConnection con) !lEV^SQJs
{ v8E:64
for(int i=1;;i++) w].DLoz
{ Dy. |bUB!f
String header=con.getHeaderFieldKey(i); 8sDw:wTC
if(header!=null) >/C,1}p[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); u{WI 4n?
Utility.log(header+" : "+con.getHeaderField(header)); epk C'
else nrpbQ(zI*
break; &JLKHwi/
} O[1Q#
} mrE>o!
PB8U+
x51p'bNy
public void splitterStop() 6S%KUFB+e
{ p0Ij4
bStop = true; = "Lb5!
} Pvkr$ou
0_>1CW+X
9J49s1
} ,5*<C'9
$Ovq}Rexc
9Kz}
/* Jn0L_@
**FileAccess.java zBrqh9%8e
*//文件访问(定位，写) ]tK<[8Y
package NetFox; G\f:H%[5[
import java.io.*; M|z4Dy
y7R{6W_U>
+{e2TY
public class FileAccessI implements Serializable{ )hA)`hL F
kf",/?s2Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 UUgc>
RandomAccessFile oSavedFile; ]'i}}/}u2
long nPos; <M3&\
&ujq6~#
h5H#xoCXp
public FileAccessI() throws IOException l(tMo7iPa
{ ~ln96*)M;
this("",0); VelX+|w
} /$ueLa
g>f_'7F&
_H2%6t/V
public FileAccessI(String sName,long nPos) throws IOException CM%;r5
{ &>auW}r
oSavedFile = new RandomAccessFile(sName,"rw"); 9fqCE619a
this.nPos = nPos; /{X2:g{
oSavedFile.seek(nPos); G-T2b,J [
} .sPa${
,#=;V"~9
V)r6bb{^
public synchronized int write(byte[] b,int nStart,int nLen) [E%Ov0OC
{ &uTK@ G+
int n = -1; cf1GA
try{ XbAoW\D(
oSavedFile.write(b,nStart,nLen); DKf:0E8
n = nLen; 8 =<&9TmE
} ji|tc9#6
catch(IOException e) :E9@9>3S
{ m&r?z%
e.printStackTrace (); 1:iT#~n
} 6/thhP3`-
'd 6z^Z6
w!^{Q'/,Q
return n; s3l:ST
} HOAgRhzE
tqe8:\1yK
d_}q.%*
} dD8f`*"*=
b6UD!tXp
o@0p
/* 9i+SU|;j
**SiteInfoBean.java -gKo@I
*/ | sio:QP
package NetFox; [6Gb@jG
]p2M!N,?
T"$yh2tSY
public class SiteInfoBean { VBK9te,A
ta 66AEc9
Jk!*j
private String sSiteURL; //Site's URL ]1 OZY@
private String sFilePath; //Saved File's Path ?N*|S)BN
private String sFileName; //Saved File's Name x:)8+Rn}
private int nSplitter; //Count of Splited Downloading File *^&2L,w
.-g++f(_i
xui.63/
public SiteInfoBean() gjVKk
{//nSplitter的缺省值为5 #A2)]XvY
//default value of nSplitter is 5 m:7$"oq|
this("","","",5); Yw\PmRL"p
} &u'$q
n_/_Y>{M0
q-fxs8+m|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C&vUZa[p
{ BM&.Tw|x
sSiteURL= sURL; Je#vl4<L
sFilePath = sPath; F#w=z/
sFileName = sName; D|}%(N@sl
this.nSplitter = nSpiltter; M8BN'%S
O!D0hW4
02_%a1g
} B9RB/vHH
:!h1S`wS
KU> $=Rd
public String getSSiteURL() wYrb P11
{ N{u4
return sSiteURL; p<2A4="&
} o#-K,|-
JEK6Ms;)A
>t,BNsWB
public void setSSiteURL(String value) cboue LEt
{ f<V#Yc(U}
sSiteURL = value; S&A, Q'
} X/_e#H0
v:MJF*/
pFLR!/J
public String getSFilePath() <wt#m`Za
{ Q3M;'m
return sFilePath; ZLBv\VQ
} {jX h/`
G] -$fz
+)#d+@-
public void setSFilePath(String value) n1n1}
{ dsKEWZ =
sFilePath = value; ZE@!s3\
} sglYT!O
HG2i^y
tK3.HvD
public String getSFileName() Q7X6OFl?
{ @aU%1h5W;l
return sFileName; $d4^e&s
} h2 2-vX
w`(EW>i
(c `t'e
public void setSFileName(String value) }|rnyYA
{ [-X=lJ:+h
sFileName = value; Vx5ioA]{
} Ux~rBv''
=}Np0UP
/ c1=`OJ
public int getNSplitter() JG xuB*}
{ #>+O=YO
return nSplitter; opQ%!["N
} pei-R
| I_,;c
=.9L/74@
public void setNSplitter(int nCount) / AFn8=9'^
{ eHCLENLmB
nSplitter = nCount; A"t~ )
} =v-BzF15
} 1$Rua
X/
HS"E3s8
/* %./vh=5)
**Utility.java tG(#&54
*/ [A?Dx-R;(
package NetFox; gF(aYuk
~y.{WuUD
rPoPs@CBD
public class Utility { `mTpL^f
,bhOIuep3
R[Q`2ggG
public Utility() vT)(#0>z
{ "'us.t.
@= f2\hU
Y4cIYUSc
} 7%C6hEP/*W
x8i;uH\8
//线程睡眠 S'>(4a
public static void sleep(int nSecond) .LDK+c
{ h2g|D(u)
try{ uK6`3lCD
Thread.sleep(nSecond); Kh<xQ:eMy
} QXZjsa_|
catch(Exception e) OfC0lb:c
{ \IJ\
e.printStackTrace (); 8Fy$'Zx'
} Pt~mpRlH
} *RugVH4
LaL.C^K
//日志 lhsd39NM
public static void log(String sMsg) +g8wc(<ik
{ t(69gF\"
System.err.println(sMsg); o<@b]ukl&
} Ag1*.t|
<}S1ZEZcQ
}LLnJl~Z
public static void log(int sMsg) Jolr"F?
{ qMT7g LB'1
System.err.println(sMsg); 23XSQHVx
} <Z%iP{
} ]Igd<
Ipo?>To
!e?;f=1+E
/* ~e,k71
**TestMethod.java u^H:z0
*/ =ML6"jr
package NetFox; u4QPO:,a4
C'x?riJ/
B WdR~|2
public class TestMethod { kfaRN^
L'k)
-QR&]U+
public TestMethod() Kn~f$1
{ ///xx/weblogic60b2_win.exe My'u('Q%
try{ :G$f)NMK
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); nbM[?=WS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); rjzRZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4$Oakl*l
fileFetch.start(); t,$4J6
} #$p&J1
catch(Exception e){e.printStackTrace ();} 'PW~4f/m
FHpS?htRy
(.~#bl
} n}?XFx!%
PveY8[i
_[ml<HW]
public static void main(String[] args) 5Ug.J{d
{ cVjs-Xf7D%
new TestMethod(); nX(2&<
} 7b7~D +b
} 4/Ub%t-
点击下载更多相关资料