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)); W(N@`^
} O9>&E;`5
for(int i=0;i<nEndPos.length-1;i++) (;^VdiJ
{ 1n7tmRl
nEndPos = nStartPos[i+1]; q5il9*)d(
} x%kS:!
nEndPos[nEndPos.length-1] = nFileLength; T7eo_Mn
} B|#*I[4`w@
} Hd(|fc{2
K-VNU
MH{$"^K
//启动子线程 #`P4s>IL1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; V9 <!pMj
for(int i=0;i<nStartPos.length;i++) %zg&eFRHI
{ %;0Llxf"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /JPyADi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wTBp=)1)f
nStartPos,nEndPos,i); q7-Eu4w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uQ4WM
fileSplitterFetch.start(); \D8d!gr
} K9Dxb
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {3Z&C$:s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y$8 >fv
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3RpDIl`0
nEndPos = " + nFileLength); ~Ein)5
// fileSplitterFetch[nPos.length-1].start(); lxTW1kr
Z IfhC'
;5tSXgGw7
//等待子线程结束 D@T>z;
//int count = 0; AtNu:U$
//是否结束while循环 oWGtKtDhH
boolean breakWhile = false; J[fjl6p
Cg NfqT0
B42.;4"T
while(!bStop) %h;~@-$
{ Bfw]#"N`
write_nPos(); M|e Qds
Utility.sleep(500); *RKYdwnb
breakWhile = true; (I~-mzu\
{4"!~W
)cc:Z7p
for(int i=0;i<nStartPos.length;i++) :4|W;Lkd!
{ wkm;yCF+
if(!fileSplitterFetch.bDownOver) 7B GMG|
{ @$ E&H`da
breakWhile = false; <F!On5=W*
break; qG.HJD
} <TmMUA)`}
} &mj98
if(breakWhile) {<7!=@j
break; ?[Xv(60]
j["b*X`8G
d[ql7
//count++; )24r^21.q
//if(count>4) `mV&[`NZ
// siteStop(); i,>yIPBU!
} (C/2shr 8
|<&9_Aq_
[>xwwm
System.err.println("文件下载结束！"); w4Nm4To
} [h7nOUL!
catch(Exception e){e.printStackTrace ();} CSx V^
} U1<EAGo|
]v7f9MC'\
+ZeHZjd
//获得文件长度 'Dyt"wfo
public long getFileSize() `(A>7;]:
{ } y@pAeS,
int nFileLength = -1; omQaN#!,
try{ r(./00a
URL url = new URL(siteInfoBean.getSSiteURL()); h32QEz-+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ikf6Y$nWfF
httpConnection.setRequestProperty("User-Agent","NetFox"); R%iyNK,
l@vaupg
3# G;uWN-
int responseCode=httpConnection.getResponseCode(); 4R-Y9:^t
if(responseCode>=400) ur^)bp<n
{ 8/X#thG
processErrorCode(responseCode); w=>~pYASH
return -2; //-2 represent access is error 4PUSFZK?
} fMRBGcg7Dc
7!Z\B-_,
-MZLkSU
String sHeader; 6tXx--Nh
,w%cX{
%(h-cuhq
for(int i=1;;i++) Fi.gf?d
{ -miWXEe@l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); CHp`4
//Utility.log(in.readLine()); YnC7e2
sHeader=httpConnection.getHeaderFieldKey(i); :X-Z|Pv8
if(sHeader!=null) Fl\X&6k
{ +grIw#j
if(sHeader.equals("Content-Length")) FHWzwi*u}
{ BG!;9Z{u
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7r,'a{Rcn
break; vKYdYa\
} z6e)|*cA$
} ]O2ku^yM
else )3g7dtq}
break; v2R41*z,
} txM R[o_
} 1'tagv?
catch(IOException e){e.printStackTrace ();} '3SS%W
catch(Exception e){e.printStackTrace ();} VF1)dd
+#~=QT9
^mr#t #[e
Utility.log(nFileLength); F;p>bw
0MDdcjqw
Kr $R"
return nFileLength; Rh#0EbE2
} AA&398F
7Yp;B:5@
ro{q':Z3
//保存下载信息（文件指针位置） ]nE_(*w
private void write_nPos() ;4<CnC**
{ nHxos`Qx
try{ 3In` !@EJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ek\fx*Lz
output.writeInt(nStartPos.length); uJVu:E.#1
for(int i=0;i<nStartPos.length;i++) EacqQFErl
{ i-oi?x<u&(
// output.writeLong(nPos); KfpDPwP@
output.writeLong(fileSplitterFetch.nStartPos); OU+oS,
output.writeLong(fileSplitterFetch.nEndPos); PGZ.\i
} kb<Nuw
output.close(); u=B_cA}:
} 9An_zrJ%i
catch(IOException e){e.printStackTrace ();} fRKO> /OT
catch(Exception e){e.printStackTrace ();} GFd~..$
} -AwR$<q'
jR<yV
`M?C(
//读取保存的下载信息（文件指针位置） c|q!C0X[
private void read_nPos() @7xb/&N
{ IxC/X5Mp^q
try{ (,$ H!qKy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); DueQ1+ P
int nCount = input.readInt(); 2Wz/s 0`
nStartPos = new long[nCount]; ~@=:I
nEndPos = new long[nCount]; 5fi6>>
for(int i=0;i<nStartPos.length;i++) K|$Dnma^n
{ ^)=c74;;
nStartPos = input.readLong(); ]UyIp`nV;
nEndPos = input.readLong(); Qo+_:N
} pjr,X+6o
input.close(); yP2[!vYw
} }5dYmny
catch(IOException e){e.printStackTrace ();} :_v/a+\n
catch(Exception e){e.printStackTrace ();} SpbOvY=>
} et]-;(M
\F=w~ $)
"<b~pfCOQk
private void processErrorCode(int nErrorCode) F*QZVg+<*X
{ sOA!Sl
System.err.println("Error Code : " + nErrorCode); I=)Hb?qT~
} F[/Bp>P7
~?&;nTwHe
2b+cz
//停止文件下载 /zZ$<mVG
public void siteStop() kOR5'rh
{ Y; =y-D
bStop = true; h-`Jd>u"
for(int i=0;i<nStartPos.length;i++) w6>'n }
fileSplitterFetch.splitterStop(); NikY0=i
!f\,xa|M
%Y8#I3jVJ
} q,-bw2
} pUby0)}t
//负责部分文件的抓取 hKv3;jcd
**FileSplitterFetch.java UlQZw*ce
*/ ]$/TsN
package NetFox; (!kOM% 3{
KB+,}7
S)Cd1`Gf
import java.io.*; B:qH7`s
import java.net.*; HrQBzS
shjbb
j48cI3C
public class FileSplitterFetch extends Thread { hEAt4z0P
[su2kOX|X
kSGFLP1FN
String sURL; //File URL }{;m:Iia_
long nStartPos; //File Snippet Start Position J =o,: 3"
long nEndPos; //File Snippet End Position K FV&Dt}<
int nThreadID; //Thread's ID [ 9)9>-
boolean bDownOver = false; //Downing is over m=i8o `
boolean bStop = false; //Stop identical E>~DlL%
FileAccessI fileAccessI = null; //File Access interface [FLRrTcE
cy|]}n85
Nzj7e 1=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [Lh<k+
{ @dE|UZ=(
this.sURL = sURL; 9d{iq"*R
this.nStartPos = nStart; %RA8M- d
this.nEndPos = nEnd; {>[,i`)
nThreadID = id; :9H=D^J
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [eL?O;@BD
} fis**f0
2= FGZa*.
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public void run() W6f?/{Oo8
{ [*zB vj}G
while(nStartPos < nEndPos && !bStop) HFYN(nz}[
{ qPsf`nI7
u '-4hU
TR3_!0
try{ +')\,m "z
URL url = new URL(sURL); Sz4YPl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )70-q yA
httpConnection.setRequestProperty("User-Agent","NetFox"); `*nVLtT Y
String sProperty = "bytes="+nStartPos+"-"; D?~`L[}I!}
httpConnection.setRequestProperty("RANGE",sProperty); BeZr5I"`}
Utility.log(sProperty); mk?&`_X1
6W&huIQ[
nQ>?{"
InputStream input = httpConnection.getInputStream(); Dp|y&x!
//logResponseHead(httpConnection); =$3]%b}
8Z{&b,Y4L
b%<-(o/
byte[] b = new byte[1024]; bL\ab
int nRead; O'y8[<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yHL2!
{ E5"%-fAJ
nStartPos += fileAccessI.write(b,0,nRead); b:Oa4vBa
//if(nThreadID == 1) En$-,8\%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F?Cx"JYix
} _r+2o-ZR
$(pzh:|
{HPKp&kl
Utility.log("Thread " + nThreadID + " is over!"); Ft)7Wx" S
bDownOver = true; T+p?VngF
//nPos = fileAccessI.write (b,0,nRead); 1,,kU
} t|q@~B :
catch(Exception e){e.printStackTrace ();} dH"wYMNL
} ?&?gQ#\N_J
} Hq'mv_}qG
(0/g)gW
%>^CD_[eO
//打印回应的头信息 0NlC|5ma)
public void logResponseHead(HttpURLConnection con) 9xL8 ];-
{ M3- bFIt
for(int i=1;;i++) F|\^O[#R
{ x*GGO)r
String header=con.getHeaderFieldKey(i); nxH+XHv
if(header!=null) TZ8:3ti
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m'D_zb9+
Utility.log(header+" : "+con.getHeaderField(header)); Y?Ph%i2E
else ?HT+| !4p
break; \xD.rBbt
} %D|p7&
} ,r\
O ;,BzA-n
@*W)r~ "~
public void splitterStop() * S4IMfp
{ 1fwjW0t
bStop = true; ]6)^+(zU
} "w3#2q&
pC<~\RR
1FC'DH!
} A/eZnsk
07pASZ;~
( <~
/* *`.h8gTD,
**FileAccess.java bHx09F]
*//文件访问(定位，写) r}>8FE9S'H
package NetFox; )EQWc0iKG
import java.io.*; "b)Y5[nW
vsc)EM ]
+o+e*B7Eh
public class FileAccessI implements Serializable{ NN(ZH73
t5 :4'%|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 n.+%eYM<
RandomAccessFile oSavedFile; z8v]Kt&
long nPos; GZY8%.1{"a
9z>I&vcX
:&*Y Io
public FileAccessI() throws IOException *d%"/l^0
{ @'UbTB!
this("",0); wuRB[KLe
} -E, d)O`;$
M\4pTcz{
SMX70T!'9
public FileAccessI(String sName,long nPos) throws IOException 3$x[{\ {
{ N|t!G^rP
oSavedFile = new RandomAccessFile(sName,"rw"); D c5tRO
this.nPos = nPos; dw'&Av' |E
oSavedFile.seek(nPos); 2d1Z;@x
} 5]_m\zn=
xz!b@5DR'%
1Pya\To,m
public synchronized int write(byte[] b,int nStart,int nLen) _:(RkS!x
{ OR84/^>
int n = -1; 2% ],0,o
try{ ./SDZ:5/
oSavedFile.write(b,nStart,nLen); xi5G?r
n = nLen; Da.eVU;
} U$zd3a_(
catch(IOException e) lG[@s 'j
{ -G\svwv@)
e.printStackTrace (); $;GH -+
} Vl"20):
<%d/"XNg[D
|"}F cS y
return n; Vf28R,~m
} c~1+5&
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B49: R>
} 6-"@j@l5<
ky2n%<0]
'mwgHo<u
/* Q,pnh!.-c
**SiteInfoBean.java "==fWf
*/ v)+E!"R3.
package NetFox; jh7-Fl`
B{}<DP.
NUSb7<s,&Y
public class SiteInfoBean { D\13fjjHlu
18*M
*dmBJi}
private String sSiteURL; //Site's URL m5c=h
private String sFilePath; //Saved File's Path OKW}8qM
private String sFileName; //Saved File's Name z@za9U`6i
private int nSplitter; //Count of Splited Downloading File nZtMF%j'
,\fp.K<
zx#HyO[a
public SiteInfoBean() mVaWbR@HS
{//nSplitter的缺省值为5 %:/@1r7o>
//default value of nSplitter is 5 g&E3Wc
this("","","",5); I 68Y4s
} hQWo ]WF(J
>z #^JR\6
pW[KC!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [P:+n7= ,l
{ io&FW!J.
sSiteURL= sURL; JxP&znng
sFilePath = sPath; fBj-R~;0
sFileName = sName; %P8*Az&]T
this.nSplitter = nSpiltter; ,J*C'#sW
l& A8P
e]9Z]a2
} P/!W']OO
\ 8v^ hb
qV$\E=%fhM
public String getSSiteURL() [SKN}:D
{ 0Dt-!Q7
return sSiteURL; Jn:h;|9w
} S4ys)!V1V
T]_]{%z
"26=@Q^Y
public void setSSiteURL(String value) R$|"eb5
{ yg@8&;bP`
sSiteURL = value; o=zr]vv
} C@o8C%o
#Sc9&DfX
o=]\Jy
public String getSFilePath() MlKSjKl" !
{ ^RI&`5g
return sFilePath; A<szY92&5
} k_?Z6RE>
1 ORA6
h_>DcVNIx
public void setSFilePath(String value) .ZtW y) U
{ [d?tf
sFilePath = value; ;T\+TZtI
} dZWO6k9[H
saa3BuV 6
5:yRFzhqd
public String getSFileName() #c%FpR4
{ v ^R:XdH
return sFileName; f1$'av
} <9dfbI)
YB}m1g`
4{lrtNd~K
public void setSFileName(String value) ^TZ`1:oL#
{ cjp~I/U
sFileName = value; ,f@\Fs~n
} xNd p]u
Oq9E$0JW
w/f?KN
public int getNSplitter() ,,c+R?D
{ ?E}9TQ
return nSplitter; 0-Ga2Go9
} =91wC
d-cW47
e>T;'7HSS"
public void setNSplitter(int nCount) ^wIg|Gc
{ i5 0c N<o
nSplitter = nCount; *S<d`mp[
} z&c|2L-u6
} |)65y
*x-@}WY$U
/O}lSXo6E
/* : i{tqY%
**Utility.java <MyT ;
*/ B,fVNpqo
package NetFox; 8n,/hY>w
LC,6hpmh
Bra}HjHO
public class Utility { -#Ys67,4N
JJHO E{%
9Ca }+
public Utility() b_vKP
{ xj[v$HP
LzQOzl@z
5AK@e|G$w
} Itz[%Dbiq9
8#nAs\^
//线程睡眠 &n'@L9v81
public static void sleep(int nSecond) IhHKRb[
{ VkkC;/BBW
try{ Jsa]RA
Thread.sleep(nSecond); ,4j^lgJ
} E?0Vo%Vh
catch(Exception e) f hjlt#
{ H+ 7HD|GE
e.printStackTrace (); tIT/HG_o
} y8ODoXk
} ,R\ex =c
N*f]NCSi
//日志 w\RYxu?
public static void log(String sMsg) jcp6-XM
{ 25j?0P"&
System.err.println(sMsg); d%K&
} V-(*{/^"
D}`MY\H
e>m+@4*sn
public static void log(int sMsg) t$3B#=
{ wBJ|%mc3TA
System.err.println(sMsg); QM'|k6
} \fsNI T/
} rvacCwI
yAFt|<
;\(LovUy6
/* CofTTYl
**TestMethod.java lA`qB1x
*/ d`,z4_
package NetFox; l{gR6U{e
i#aKW'
o)GesgxFa5
public class TestMethod { #w@FBFr@
|\Q2L;4C
YwS/O N
public TestMethod() &Oc `|r*
{ ///xx/weblogic60b2_win.exe fRb
try{ h$XoR0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !sp`oM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q"5\bh1"
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'ka}x~EF
fileFetch.start(); rd;E /:`5
} #uV J
catch(Exception e){e.printStackTrace ();} ;9Qxq]
|~@yXc5a
P!SsMo6n
} $:yIe.F
vJ{F)0 K
F1S0C>N?5
public static void main(String[] args) v 8EI
{ Nt;1&dwUb
new TestMethod(); 1*e7NJ/.,
} dlA0&;}z
} Xf{9rZ+
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