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)); \zUsHK?L"t
} NC}#P<U
for(int i=0;i<nEndPos.length-1;i++) u|c+w)a
{ -Me\nu8(RF
nEndPos = nStartPos[i+1]; A.b#r[
} ^xwFjQXx
nEndPos[nEndPos.length-1] = nFileLength; (Wqhuw!u
} wW4S@m
} i]z i[Zo$
h(-&.Sm")H
!)=o,sVA
//启动子线程 CmOb+:4@K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I1~g?jpH
for(int i=0;i<nStartPos.length;i++) ;GSJnV
{ 2LU'C,o?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M\f0 =`g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ? h%+2
nStartPos,nEndPos,i); =.a ]?&Yyh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M6sDtL9l
fileSplitterFetch.start(); s|'L0` <B
} (/U1J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @\?f77Of6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3D0I5LF&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", z<>_*Lfj
nEndPos = " + nFileLength); ^@2Vh*k
// fileSplitterFetch[nPos.length-1].start(); #Au&2_O
b*KZe[#M1
W\7*T1TDj
//等待子线程结束 v_0!uT5~NE
//int count = 0; KoJG!Rm
//是否结束while循环 r `dU (T!
boolean breakWhile = false; Tt|6N*b'
* U4:K@y
sBnPS[Oo
while(!bStop) *lAdS]I
{ <*(R+to^d
write_nPos(); @`D6F;R
Utility.sleep(500); lv*uXg.k^
breakWhile = true; 9,CC1f
P;&p[[7
N~jQ!y
for(int i=0;i<nStartPos.length;i++) p%1m&/`F
{ [!mjUsut*
if(!fileSplitterFetch.bDownOver) 1.uQ(>n
{ ($>0&w
breakWhile = false; ;7k7/f:
break; >>zoG3H!
} RzQS@^u*F0
} QOk"UP
if(breakWhile) zP}v2
break; )6^xIh
w.p'Dpw
t8 "-zd8
//count++; "lf3hWGw
//if(count>4) jqWvLBU!
// siteStop(); ^ZUgDQduc
} ~+yo;[1Yc
GTl(i*
Els=:4
System.err.println("文件下载结束！"); [uQZD1<q
} J94YMyOo
catch(Exception e){e.printStackTrace ();} d|RmU/)
} >:&p(eu)L0
GQq'~Lr5
LB7I`W
//获得文件长度 v^fOT5\
public long getFileSize() lG>e6[Wc
{ :0/o?'s
int nFileLength = -1; b]?;R
try{ x)ZH;)
URL url = new URL(siteInfoBean.getSSiteURL()); RLNuH2y;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .6o y>4
httpConnection.setRequestProperty("User-Agent","NetFox"); }F6b ]
G| oG:
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int responseCode=httpConnection.getResponseCode(); %nf=[f
if(responseCode>=400) g8A{aHb1}
{ C)p<M H<
processErrorCode(responseCode); %5?-g[
return -2; //-2 represent access is error B RjKV
} 4^_Au^8R(
d ovwB`5
^l&4UnLlc
String sHeader; XYF~Q9~
VQMd[/
}A/&]1GWk
for(int i=1;;i++) 6F/ OlK<
{ jYID44$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k+GnF00N^8
//Utility.log(in.readLine()); bI6wE'h
sHeader=httpConnection.getHeaderFieldKey(i); 7Sq{A@ET
if(sHeader!=null) +{!t~BW
{ cG!2Iy~lA
if(sHeader.equals("Content-Length")) ]f-'A>MC
{ 00a<(sS;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #'J7Wy
break; L$c%u
} f?^Oy!1]
} y"p-8RVk{
else PFgjWp"Y
break; l'".}6S
} QYw4kD}
} >E ;o"
catch(IOException e){e.printStackTrace ();} edk9Qd9
catch(Exception e){e.printStackTrace ();} T-2p`b}hW
{)9HS~e T
N<"6=z@w+
Utility.log(nFileLength); RdvTtXg
6ri?y=-c
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return nFileLength; m3Z}eC8LK
} r9a!,^}F
&t|V:_?/x
AYu'ptDNr
//保存下载信息（文件指针位置） !2U7gVt"*
private void write_nPos() Mth`s{sATa
{ @j2*.ee
try{ }rA+W-7
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~K$"PKs3
output.writeInt(nStartPos.length); $0S#d@v}
for(int i=0;i<nStartPos.length;i++) 4\SBf\ c
{ ) wo2GF
// output.writeLong(nPos); [Ro0eH
output.writeLong(fileSplitterFetch.nStartPos); ~EWfEHf*BJ
output.writeLong(fileSplitterFetch.nEndPos); t,1!`/\
} 5QFXj)hR+4
output.close(); {e[pSD6
} AH87UkNL
catch(IOException e){e.printStackTrace ();} LO}:Ub
catch(Exception e){e.printStackTrace ();} 2{]S_. zV
} .Jat^iFj0
Q()RO*9
-1r&s
//读取保存的下载信息（文件指针位置） QD;f~fZ
private void read_nPos() (6#yw`\
{ MD ?F1l"}%
try{ X)iWb(@k"7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B6'%J
int nCount = input.readInt(); LVFsd6:h
nStartPos = new long[nCount]; uyRA`<&w
nEndPos = new long[nCount]; 7}tZ?vD
for(int i=0;i<nStartPos.length;i++) s!;VUr\
{ pg}+lYGP
nStartPos = input.readLong(); .UhBvHH
nEndPos = input.readLong(); U>_\
} ,dj*p,J
input.close(); 6n6VEwYj
} /mBBeg^a
catch(IOException e){e.printStackTrace ();} 6:@t=C
catch(Exception e){e.printStackTrace ();} e(;`9T
} 'UvS3]bSYW
2HK
kGuk -P
private void processErrorCode(int nErrorCode) R4~zL!7;
{ Wt)SdF=U/
System.err.println("Error Code : " + nErrorCode); ZH$sMh<xg
} 8}?Y;>s\
)lDIzLp
p-'6_\F.Ke
//停止文件下载 NzeI/f3K5
public void siteStop() 'f?&EsIV?
{ eFj6p<
bStop = true; _z(5e
for(int i=0;i<nStartPos.length;i++) o&XMgY~
fileSplitterFetch.splitterStop(); w^'?4M!
.xLF}{u
,7fc41O3V
} '=Kof1
} C/CfjRzd
//负责部分文件的抓取 #?$'nya*u
**FileSplitterFetch.java X#kjt)W
*/ ZP63Alt
package NetFox; u_6BHsU
_+Jf.n20
|1QbO`f/F
import java.io.*; dp[w?AMhM9
import java.net.*; B/sBYVU
Id.Z[owC`Y
rxy{a
public class FileSplitterFetch extends Thread { |:e|~sism
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^L8Wn6s'
String sURL; //File URL io9xI3{
long nStartPos; //File Snippet Start Position # +QWi0B
long nEndPos; //File Snippet End Position InPy:}
int nThreadID; //Thread's ID jqX@&}3@
boolean bDownOver = false; //Downing is over >Z2,^5P{
boolean bStop = false; //Stop identical /\-2l+y>J
FileAccessI fileAccessI = null; //File Access interface =,C9O
3u?`q%Y-e
FfYd+]+?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException E&];>3C
{ s=nVoc{Yt
this.sURL = sURL; "'F;lzq
this.nStartPos = nStart; ( *9Ip
this.nEndPos = nEnd; ,\S pjE
nThreadID = id; 0 .FHdJ<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1~R$$P11[9
} R*Xu(89
0tW<LR-}E
Pn+IJ=0Y
public void run() &'huS?gA9
{ U50s!Zt45
while(nStartPos < nEndPos && !bStop) $/, BJ/9
{ Y[iDX#
62MRI
@QVqpE<|
try{ oTF^<I-C
URL url = new URL(sURL); _^6|^PT.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @3-,=x
httpConnection.setRequestProperty("User-Agent","NetFox"); a)_rka1(
String sProperty = "bytes="+nStartPos+"-"; l- 1]w$ y
httpConnection.setRequestProperty("RANGE",sProperty); SY$J+YBLM
Utility.log(sProperty); ol$2sI=.s
>&<<8Ln
p|\%:#
InputStream input = httpConnection.getInputStream(); {*?sVAvj
//logResponseHead(httpConnection); @q> ktE_
GP[6nw_'^
<DeKs?v
byte[] b = new byte[1024]; Ue{vg$5||
int nRead; X!7VyE+n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ] Wx>)LT
{ HBh` 2Q
nStartPos += fileAccessI.write(b,0,nRead); mFqSD
//if(nThreadID == 1) " K 8&{=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e}'#Xv
} ^])e[RN7?n
zd*3R+>U'>
ocIt@#20K
Utility.log("Thread " + nThreadID + " is over!"); #cj\~T.,,
bDownOver = true; .1.J5>/n
//nPos = fileAccessI.write (b,0,nRead); $=PWT-GIR
} Qy=HrL]x
catch(Exception e){e.printStackTrace ();} \Y!T>nWn)I
} lX98"}
} ]a$Wxvgq
[F/^J|VMV
;dqk@@O"(
//打印回应的头信息 JQ)4}t
public void logResponseHead(HttpURLConnection con) JkSdLj
{ yaH Trh%
for(int i=1;;i++) -ajM5S=d*
{ IPl@ DH
String header=con.getHeaderFieldKey(i); SwdC,
if(header!=null) I#|ocz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .q0218l:dF
Utility.log(header+" : "+con.getHeaderField(header)); .O5LI35,
else r-RCe3%g%
break; w=f0*$ue+w
} |Z`M*.d+
} gd337jw
Sao>P[#x
*:=];1O
public void splitterStop() UGhW0X3k
{ (;;J,*NP
bStop = true; pOqGAD{D$
} .MDYGWKt
nE/=:{~Ws
uy/y wm/?=
} .A3DFm3t
gw_|C|!P
JN9^fR09G
/* XzlKP;r0
**FileAccess.java r1i$D
*//文件访问(定位，写) `IEq@Wr#$!
package NetFox; %ZujCZn
import java.io.*; x}tKewdOSe
<jbj/Q )"
`1nRcY
public class FileAccessI implements Serializable{ Eo%UuSi
+yzcx3<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Tr}R`6d$
RandomAccessFile oSavedFile; MKU7fFN.
long nPos; u-m%=2
[NYj.#,oR
IE&_!ce
public FileAccessI() throws IOException JXpoCCe
{ >|wKXz
this("",0); - #3{{
} y L*LJ
\r)%R5_CQ
h^}_YaT\
public FileAccessI(String sName,long nPos) throws IOException yZq?B
{ 's)fO#
oSavedFile = new RandomAccessFile(sName,"rw"); G49Ng|qn
this.nPos = nPos; )T>8XCL\}
oSavedFile.seek(nPos); 82lr4
} \X&]FZ(*
<5dH *K
KwS`3 6:
public synchronized int write(byte[] b,int nStart,int nLen) zQ,f5x
{ m&Lt6_vi
int n = -1; Z.!g9fi8>
try{ egfi;8]E
oSavedFile.write(b,nStart,nLen); Osnyd+dJY
n = nLen; E]NY (1
} f%c06Un=
catch(IOException e) "X`RQ6~]>
{ r,5-XB
e.printStackTrace (); Q~phGD3!~
} +9RJ%i&Ec
Bb~5& @M|N
l{8CISO*
return n; `%|u!
} qYx!jA]O
B$ui:R/ t
;TtaH
} 0A.PD rM:
2xDQ:=ec
J==}QEhQ{
/* ?FN9rhAC
**SiteInfoBean.java j~epbl)pC
*/ B22b&0
package NetFox; [a@B =E
' PELf P8
>)LAjwhBp
public class SiteInfoBean { a2o.a2
>rKhlUD
zhX;6= X2
private String sSiteURL; //Site's URL 7{-@}j`
private String sFilePath; //Saved File's Path X<Z(]`i
private String sFileName; //Saved File's Name _ \l HI
private int nSplitter; //Count of Splited Downloading File K5{{:NR$
QP:9%f>=
.:8[wI_f
public SiteInfoBean() pw=F' Y@N
{//nSplitter的缺省值为5 hcyn
//default value of nSplitter is 5 }wfI4?}j}
this("","","",5); ^p,3)$
} }t\ 10nQ
?~,JY
gwiR/(1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Tv\HAK<N
{ ~ 7}]
sSiteURL= sURL; /_q#ah
sFilePath = sPath; M|k&TTV
sFileName = sName; vO]J]][
this.nSplitter = nSpiltter; to'j2jP
,ijW(95{k
)A"jVQjI%w
} PK+ x6]x
gKWzFnW
uN9e:;
public String getSSiteURL() ailG./I+
{ +#~O'r]%GG
return sSiteURL; dMJ!>l>2
} jB!W2~Z
Y''6NGf
a%E8(ms37y
public void setSSiteURL(String value) OF8WDo`
{ 12lEs3
sSiteURL = value; 4:U0f;Fs
} dKm`14f]@G
Aq"PG}Ic
yX'IZk#_L
public String getSFilePath() KaW~ERx5
{ Rboof`pVt
return sFilePath; ,Aj }]h\L
} wu2:'y>n
#EG?9T
1i3V!!r
public void setSFilePath(String value) /'4Q{8.a
{ EjSD4
sFilePath = value; yp p4L|R
} 4{Udz!
=&2$/YX0D
MtUY?O.P2
public String getSFileName() 6.'$EtH
{ E~RV1)
return sFileName; Sph*1c(R
} *Tp]h 0
=/Wu'gG)
@+&'%1
public void setSFileName(String value) 4gOgWBv
{ | 3giZ{
sFileName = value; | ]# +v@
} C_G1P)k
IY)5.E _
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public int getNSplitter() TV=c,*TV
{ K2HvI7$-
return nSplitter; ZoxS*Xk
} X2^_~<I{,
N@()F&e
o,FUfO}F
public void setNSplitter(int nCount) G3dhM#!
{ mgVML&^
nSplitter = nCount; f=m/ -mAA
} o?wt$j-
} l3p3tT3+
&SmXI5>Bo0
U:n*<l-k}
/* EkZjO Ci
**Utility.java K]<u8eF
*/ b[srG6{ &
package NetFox; o1k#."wHr
OQFi.8
F;kvH
public class Utility { KjOi(YUnq7
@9vvR7{P
ffk4mhH
public Utility() wyw<jH
{ tS<h8g_
XWtiwf'K
nY0sb8lZJ
} hVUIBJ/5(-
WNF9#oN|oT
//线程睡眠 $XGtS$
public static void sleep(int nSecond) iBoEZEHjw
{ <hv7s,i
try{ lFfXWNb
Thread.sleep(nSecond); Dm%%e o
} s.:r;%a
catch(Exception e) aZKXD! 4
{ J3B.-XJ+n
e.printStackTrace (); VR4%v9[1
} y|sma;D
} {mSJUK?TKl
8lwM{?k$
//日志 ^ ulps**e
public static void log(String sMsg) K-(;D4/sQE
{ d>!p=O`>{q
System.err.println(sMsg); {/ &B!zvl
} h8=h >W-
Qra>}e%*
RmOyGSO
public static void log(int sMsg) 4seciz0?
{ Rp/-Pv
System.err.println(sMsg); -H\,2FO
} O2v.
} FH*RU1Z
]XUSqai
hYb9`0G"2
/* C`4gsqD;Z
**TestMethod.java d(S}NH
*/ 10MU-h.)
package NetFox; \hbiU]
|ym%| B
H/J<Pd$p
public class TestMethod { U3F3((EYJ
^~l $&~
maDz W_3
public TestMethod() *#2Rvt*Ox
{ ///xx/weblogic60b2_win.exe O,mip
try{ Of`c`-<j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]k*1KP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,4Y*:JU4
SiteFileFetch fileFetch = new SiteFileFetch(bean); [6RfS
fileFetch.start(); $bGD%9 z
} I=[cZ;t
catch(Exception e){e.printStackTrace ();} &&PgOFD
SRCOs1(EK9
%&<W(|U1<
} 4*M@]J "
p4wr`"Zz
V`k8j-*s
public static void main(String[] args) I7mG/
{ IKcKRw/O$
new TestMethod(); a+?~;.i~
} n93zD*;5
} )(bxpW
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