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)); sqkPC_;A
} ~< k'{
for(int i=0;i<nEndPos.length-1;i++) Z*oGVr g
{ (l$bA_F\
nEndPos = nStartPos[i+1]; h-6kf:XP%
} Iz ,C!c
nEndPos[nEndPos.length-1] = nFileLength; 1c\$ziB
} ^c/.D*J[I
} O6m}#?Ai/@
WyO10yvR
h>fY'r)DAx
//启动子线程 -()CgtSR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X)'uTf0
for(int i=0;i<nStartPos.length;i++) TT>;!nb
{ b&0q%tCK
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >y2gfD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5I@< 6S&X
nStartPos,nEndPos,i); -l^u1z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k3u3X~u
fileSplitterFetch.start(); lh .p`^v
} /5SBLp}Sy
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Es)Kw3^a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [X;yJ$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l].dOso$`
nEndPos = " + nFileLength); }]/"auk
// fileSplitterFetch[nPos.length-1].start(); 2x t 8F
yv&&x.!.Z
CGPPo;RjK
//等待子线程结束 t}]=5)9<
//int count = 0; =r#of|`Q
//是否结束while循环 wOn.m
boolean breakWhile = false; LKTIwb>
#5=Yg5
QYDSE
while(!bStop) >DPC}@Wl
{ 6"z:s-V
write_nPos(); e![n$/E3R
Utility.sleep(500); jq%Qc9y
breakWhile = true; l7nc8K
7<=xc'*8t
>]s|'HTxF
for(int i=0;i<nStartPos.length;i++) ;3 O0O
{ KHI-m9(
if(!fileSplitterFetch.bDownOver) }[\l$sS
{ ;&oS=6$
breakWhile = false; !T!U@e=u
break; 2ntL7F<ow
} b:SjJA,HM
} r".*l?=
if(breakWhile) **N{XxdN
break; M2l0x @|
]MKW5Kq
Uf4A9$R.G
//count++; (p>?0h9[
//if(count>4) hxZ5EKBy
// siteStop(); !:]CKbG
} Nawph
5_!s\5
=^\yE"a
System.err.println("文件下载结束！"); zmB6Y t
} H|JPqBNRh
catch(Exception e){e.printStackTrace ();} r~nD%H:}P
} \,&,Q
{<+B>6^
(E[c-1s
//获得文件长度 ~.7/o0'+
public long getFileSize() Ve)P/Zz}^
{ \MI2^JN
int nFileLength = -1; lY -2e>
try{ uGt}Hn
URL url = new URL(siteInfoBean.getSSiteURL()); =p{55dR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3b{ 7Z 2
httpConnection.setRequestProperty("User-Agent","NetFox"); =S+*=jA
B8.a#@R
=>3wI'I
int responseCode=httpConnection.getResponseCode(); 1*U)\vK~
if(responseCode>=400) 8z1#Q#5
{ BA(erf>
processErrorCode(responseCode); &tVIl$e
return -2; //-2 represent access is error 3EkCM_]
} h@AKfE!\~
;YN`E
Aqy y\G;
String sHeader; 2i0 .x
LuW>8K\
yM}~]aQ y
for(int i=1;;i++) u1 Z;n
{ |#(KP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (;!92ct[?
//Utility.log(in.readLine()); )_C+\K*
sHeader=httpConnection.getHeaderFieldKey(i); d?ru8
if(sHeader!=null) cV$an
{ S@Iza9\|@
if(sHeader.equals("Content-Length")) |qs8( 5z0
{ U1ZKJ<pv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); YuXCRw9p;
break; `uP:UQ9S
} C]EkVcKFA
} yE&WGpT
else ThvgYv--B
break; Zh
} +$}3=n34)
} LUs)"ZAi|
catch(IOException e){e.printStackTrace ();} *O|_)G
catch(Exception e){e.printStackTrace ();} ObPXVqG"?
'kOkwGf!
!n7'TM'
Utility.log(nFileLength); hv0bs8h
8TBv~Qu
S;0z%$y
return nFileLength; @ D,]v:
} O=[Q>\p
;~-ZN?8
q4#$ca[_ak
//保存下载信息（文件指针位置） DFkDlx
private void write_nPos() S,Z~-j
{ Wsb>3J
try{ q4ttmL8
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3+l8VX&u!
output.writeInt(nStartPos.length); 2YDD`:R
for(int i=0;i<nStartPos.length;i++) "XQ3mi`y
{ }_Ci3|G>%D
// output.writeLong(nPos); ds9U9t
output.writeLong(fileSplitterFetch.nStartPos); })+iAxR
output.writeLong(fileSplitterFetch.nEndPos); {'Y()p3kl
} /a*8z,x
output.close(); ?y-@c]
} F EUfskv
catch(IOException e){e.printStackTrace ();} Y\Z6u)
catch(Exception e){e.printStackTrace ();} )&DsRA7v
} 8J#xB
j0=F__H#@
2"T b><^"
//读取保存的下载信息（文件指针位置） u6 QW*8b4
private void read_nPos() /lC,5y
{ ^F'~|zc"C
try{ <&^[?FdAa
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mGDy3R90
int nCount = input.readInt(); XuWX@cK
nStartPos = new long[nCount]; \QQWhwE
nEndPos = new long[nCount]; h3bQ<?m
for(int i=0;i<nStartPos.length;i++) deQ{
{ \2!.
nStartPos = input.readLong(); >k ==7#P
nEndPos = input.readLong(); ce;$)Ff\
} Oq$-*N
input.close(); YZ]}l%e
} x+DETRLP
catch(IOException e){e.printStackTrace ();} NT2XG&$W>
catch(Exception e){e.printStackTrace ();} k.7!)jL7
} qzNXz_#+u
n=)LB& m
pTaC$Ne
private void processErrorCode(int nErrorCode) lI%RdA[
{ dWi<U4
System.err.println("Error Code : " + nErrorCode); 2}7_Y6RS*
} aS[y\9(**
7IFZK\V
>0[:uu,'>
//停止文件下载 pHx$
public void siteStop() MLlvsa0
{ A9g/At_
bStop = true; "N">RjJ"
for(int i=0;i<nStartPos.length;i++) j D*<M/4
fileSplitterFetch.splitterStop(); b)x0;8<
urE7ZKdI
m]*a;a'}#
} RT3(utwO
} =>lX brJ
//负责部分文件的抓取 FaWDAL=Vhk
**FileSplitterFetch.java o=#ym4hJ%
*/ ]%I\FefT
package NetFox; j'Jb+@W?
j/Y]3RSMp
u Fw1%
import java.io.*; kN3 <l7
import java.net.*; IA&V?{OE@I
0Gc:+c7{
#_x5-?3
public class FileSplitterFetch extends Thread { r73W.&
',!jYh}Uxk
{chZ&8)f
String sURL; //File URL PH&Qw2(Sx
long nStartPos; //File Snippet Start Position j!NXNuy:
long nEndPos; //File Snippet End Position Qe7=6<
int nThreadID; //Thread's ID 7.Z-
boolean bDownOver = false; //Downing is over b{,v?7^4
boolean bStop = false; //Stop identical (J.Z+s$:2
FileAccessI fileAccessI = null; //File Access interface *U6+b
oK-d58 sM
?<BI)[B
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wkPjMmW+!
{ 9_d#F'#F
this.sURL = sURL; _68vSYr
this.nStartPos = nStart; +c!HXX
this.nEndPos = nEnd; Y3~z#<
nThreadID = id; F!g1.49""
fileAccessI = new FileAccessI(sName,nStartPos);//定位 i$p2am8f
} [ `1`E1X
h~]e~u V
R) :Xs.
public void run() ;]0d{
{ P_0[spmFU
while(nStartPos < nEndPos && !bStop) JFO,Q -y\
{ iZiT/#,H2
jIr\.i
/n(0w`
try{ 2A@oa9
URL url = new URL(sURL); l'_]0%o]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~E((n
httpConnection.setRequestProperty("User-Agent","NetFox"); &L5 )v\z
String sProperty = "bytes="+nStartPos+"-"; QW,:'\G
httpConnection.setRequestProperty("RANGE",sProperty); _b/zBFa%
Utility.log(sProperty); {]8|\CcY?
OI6Mx$
eR>8V8@
InputStream input = httpConnection.getInputStream(); MZX)znO
//logResponseHead(httpConnection); ZiQ<SSo:
oy#(]K3`O
+>1?ck
byte[] b = new byte[1024]; h%$^s0w
int nRead; QwpX3 k6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1eV&oN#
{ U^GVz%\
nStartPos += fileAccessI.write(b,0,nRead); I<sUB4T>#W
//if(nThreadID == 1) jUNt4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mF~]P8
} ~+0IFJ`}
=y@0il+V
&v*4AZ['
Utility.log("Thread " + nThreadID + " is over!"); `?R{sNr.
bDownOver = true; =^rp= Az
//nPos = fileAccessI.write (b,0,nRead); onRTX|#
} hp/pm6
catch(Exception e){e.printStackTrace ();} >KP,67
} Ri`6X_xU
} \+sa[jK
elhP!"G
1aIGC9xQ`
//打印回应的头信息 +aEm]=3
public void logResponseHead(HttpURLConnection con) ,D }Ka?
{ PDw+Q
for(int i=1;;i++) "|dhmV[;
{ fPKpV`Hr3
String header=con.getHeaderFieldKey(i); W).Kq-
if(header!=null) Kf[.@_TD<1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %5zIh[!1$
Utility.log(header+" : "+con.getHeaderField(header)); !e<2o2~.
else gt.F[q3
break; 'v0rnIsI?
} tF-l=ph}`
} Zqe$S +u
!lFNG:&`
fgj$ u
public void splitterStop() # }}6JM
{ 1Dhe! n#
bStop = true; @|t]9
} ^swj!da
=8tK]lb
"\}h
} Qb)c>r
. 70=xH
GT]>
/* TW(X#T@Z6I
**FileAccess.java +HUy,@^Pa
*//文件访问(定位，写) r_Ou\|jU
package NetFox; MbInXv$q2/
import java.io.*; n CX{tqy
=X5w=(&
mejNa(D ^
public class FileAccessI implements Serializable{ #T>?g5I
O>nMeU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 dr&G>
RandomAccessFile oSavedFile; s1::\&`za
long nPos; cU ?F D
rA?<\*
y5aPs z
public FileAccessI() throws IOException _U4@W+lhX_
{ d6[' [dG
this("",0); e&T-GL
} rf@47H
|1A0YjOD
2NjgLXP
public FileAccessI(String sName,long nPos) throws IOException R(&3})VOa
{ GLZ*5kw
oSavedFile = new RandomAccessFile(sName,"rw"); i g7|kl
this.nPos = nPos; b|Ge#o
oSavedFile.seek(nPos); (91ts$jH
} FMF mn|
SKNHLE}
d&|5Rk ~
public synchronized int write(byte[] b,int nStart,int nLen) owA8hGF
{ pYAKA1F
int n = -1; [!3cWJCt
try{ 3$P
oSavedFile.write(b,nStart,nLen); I Ij:3HP
n = nLen; wVI_SQ<8V
} L..
catch(IOException e) L.-qTh^P
{ Ho*B<#&(A|
e.printStackTrace (); <zTz/Hk`
} )[UYCx'
XHKLl?-
7CF>cpw
return n; 3w p@OF_
} ~rjK*_3/
8;<aco/62
lg )xQV
} SQU@JKi;g
'?.']U,: $
>jTiYJI_M
/* Lh-Y5(c o
**SiteInfoBean.java bYem0hzOe
*/ ZR|s]'
package NetFox; e&ZH 1^O
7 u Q +]d
l'2vo=IQ
public class SiteInfoBean { VE/m|3%t
L">jSZW[[
kt_O=
private String sSiteURL; //Site's URL ]xb2W~
private String sFilePath; //Saved File's Path Si23w'T
private String sFileName; //Saved File's Name wfu`(4
private int nSplitter; //Count of Splited Downloading File GeB-4img
XJl 3\*
*'M+oi
public SiteInfoBean() w&es N$2
{//nSplitter的缺省值为5 E;4dlL`*
//default value of nSplitter is 5 OaoHN& "
this("","","",5); V^n=@CZT9C
} 4~oRcO8!Y
4XiQ8"C
MZX@Gi<S[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y9@j-m&
{ ~K|ha26W
sSiteURL= sURL; gth_Sz5!#
sFilePath = sPath; t(.vX
sFileName = sName; Abmi=]\bx
this.nSplitter = nSpiltter; g.8^ )u
\7$"i5
;8e}X6YU
} c;yp}k]\
4 s9^%K\8{
&h6 `hP_
public String getSSiteURL() {m,LpI0wG
{ ?wIEXKI
return sSiteURL; ZN'B@E=p
} D^];6\=.i
q/@r#
{VM^K1
public void setSSiteURL(String value) .]<iRf[\[
{ J=O_nup6C
sSiteURL = value; nS.qK/.s
} A~0yMww:$
6Rg>h
Y~#.otBL&
public String getSFilePath() fp3`O9+em
{ 4Uwcc):f
return sFilePath; G-vkkNj%e
} 7}&vEc@w&
"1DlusmCCB
{[{jlG4H
public void setSFilePath(String value) )7E7K%:b,
{ ,K&L/*
sFilePath = value; v806f8
} t|UM2h
Kj4L PG
2j{T8F\]
public String getSFileName() RO'b)J:j9
{ $c+:dO|Fb
return sFileName; +J42pSxzoo
} ojIGfQV
J/Ch /Sa
69odE+-X.
public void setSFileName(String value) HMKogGTTo
{ IFF1wfC
sFileName = value; 9!Fg1h=
} H$zDk
!(j<Y0xo:
%~lTQCPE
public int getNSplitter() /(}YjeS
{ G{a_\'7
return nSplitter; ~Hb0)M@y7
} Q$yQ^ mG
bWZzb&
_znn`_N:v
public void setNSplitter(int nCount) QT(]S>--n
{ Jb7^'P
nSplitter = nCount; h{ EnS5~
} (S&D
} NV2$ >D
j4(f1
{^R"V ,)
/* ;T>.
**Utility.java ?y~"\iP
*/ T&E'MB
package NetFox; LdX'V]ITh
U)('}u=b
z&.F YGq}
public class Utility { srS5-fs
(Ii+}Mfp
gI+dyoh
public Utility() S$GWY^5}{
{ )u=a+T
<;!#+|L/
19\ V@d^
} 8;(3fSNC
qI2&a$Zb$
//线程睡眠 Rw!_j!
public static void sleep(int nSecond) -JdNA2P
{ e1R<+`]
try{ U/{#~P5s
Thread.sleep(nSecond); gt(!I^LHYc
} mqQC`Aqx:
catch(Exception e) .JWN\\
{ {jEEAH)
e.printStackTrace (); FBA th !E
} rJCu6
} lnrs4s Km
Rw`64L_
//日志 *7yrm&@nG
public static void log(String sMsg) Ce@"+k+w
{ %Lfy!]Ru
System.err.println(sMsg); Q\*zF,ek
} mFuHZ)iQG
W!b'nRkq
|I=GI]I
public static void log(int sMsg) < _<?p&
{ v}uzUY
System.err.println(sMsg); cg}lF9;d
} n,b6|Y0
} S 0mt8/ M
j k/-7/r
?s9f}>
/* eY'RDQa
**TestMethod.java F Xp_`9.zH
*/ ^J&}C
package NetFox; rTA#4.*&
q.d qr<
?l](RI
public class TestMethod { Lz`_&&6
3q0S}<h al
y7.oy"
public TestMethod() SM[VHNr,-
{ ///xx/weblogic60b2_win.exe [LKzH!
try{ O|0,= 5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z" dU$,n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); wI#R\v8(`n
SiteFileFetch fileFetch = new SiteFileFetch(bean); x8RiYi+
fileFetch.start(); W-4R;!42
} Eyg F,>.4
catch(Exception e){e.printStackTrace ();} sO8F0@%aH(
23P7%\
aoU5pftC
} Ew&|!d
| =tGrHL
eZmwF@
public static void main(String[] args) fWl #CI\]
{ >ToI$~84
new TestMethod(); opon"{
} a- 7RJ.
} 2:&QBwr+;
点击下载更多相关资料