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)); f%{Tu`
} ;:c%l.Y2
for(int i=0;i<nEndPos.length-1;i++) BZ?W>'B%$
{ aEDN]O95?
nEndPos = nStartPos[i+1]; O|Ic[XfLx
} C|f7L>qe
nEndPos[nEndPos.length-1] = nFileLength; tHtV[We.:
} /Tj"Fl\h
} Tdwwtbe
,%h!%nz!
R9l7CJM@
//启动子线程 "F"_G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >Mn>P!
for(int i=0;i<nStartPos.length;i++) {1MGb%xW
{ v{2DBr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tin|,jA =
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;a#*|vx
nStartPos,nEndPos,i); *9vA+uN
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ey)u7-O
fileSplitterFetch.start(); ZCBPO~&hO'
} F:J7|<J^F
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^W"Q(sh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %kx ^/DH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !&`\ LJ=j
nEndPos = " + nFileLength); n`)7Y`hBhP
// fileSplitterFetch[nPos.length-1].start(); Ao":9r[V
)M'UASB;8
~"0@u
//等待子线程结束 _~[?>cF%
//int count = 0; JT|u;Z*n
//是否结束while循环 ?{: D,{+
boolean breakWhile = false; GzFE%< 9F
,<3uc
Hl3)R*&'J
while(!bStop) 3u*hTT
{ UQ3@@:L_
write_nPos(); kwHqvO!G
Utility.sleep(500); VkpHzr[k
breakWhile = true; k\pDJ7wF^
Mi}I0yhVm
5_)@B]~nM
for(int i=0;i<nStartPos.length;i++) 3eTrtCe$
{ YN@6}B#1
if(!fileSplitterFetch.bDownOver) NLQE"\#a
{ %)axGbZG;
breakWhile = false; OB6J.dF[%
break; Vf0fT?/K
} \CK(;J
} xHB/]Vd-
if(breakWhile) GVG!sMmnX
break; 8PBU~mr
*q*HGW5
nG"n-$A?<
//count++; !&`}]qQZ
//if(count>4) "#pzZ)Zh
// siteStop(); >+ ]R4
} S= -M3fP~
V5a?=vK9
2vc\=
System.err.println("文件下载结束！"); vUYJf99B
} A)hhnb0o
catch(Exception e){e.printStackTrace ();} !7*(!as
} efjO8J[uk-
.Z=Ce!
I1)-,/nEjg
//获得文件长度 )'5<6Q.]
public long getFileSize() %X4-a%512
{ ivzAlwP
int nFileLength = -1; v**z$5x9
try{ d(fPECv(
URL url = new URL(siteInfoBean.getSSiteURL()); gF[6c`-s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M!gBmQZ1
httpConnection.setRequestProperty("User-Agent","NetFox"); hr$Sa
?j/kOD0
_BV`,`8}
int responseCode=httpConnection.getResponseCode(); QqtC`H\
if(responseCode>=400) Hz?!BV0
{ P8wy*JvT
processErrorCode(responseCode); ptpW41t}^
return -2; //-2 represent access is error oYz!O]j;a
} tAqA^f*{
x(PKFn
k6Ihc?HL
String sHeader; gYatsFyL
53 @oP
(*,8KLV_i
for(int i=1;;i++) )O3jQ_q=
{ QjA&IZEC
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b~_B [cf
//Utility.log(in.readLine()); 4:vTxNs&S
sHeader=httpConnection.getHeaderFieldKey(i); $!G`D=
if(sHeader!=null) ]@X{dc
{ Xb}!0k/{
if(sHeader.equals("Content-Length")) qy_%~c87
{ '>3`rsu
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =}JBA>q(
break; &%^K,Q"
} k-"<{V
} ]9jZndgC
else ^m*3&x8
break; E4+b-?PB~
} 6Rcua<;2P
} ~TDzq -U)
catch(IOException e){e.printStackTrace ();} ;XG]Q<S\
catch(Exception e){e.printStackTrace ();} BhKO_wQ?:J
L=,OZ9aA
&1wpGJqm
Utility.log(nFileLength); rA,CQypo
Xv0F:1
K@HQrv<
return nFileLength; \a\= gn
} U98_M)-%&
->\N_|_
P5xI
//保存下载信息（文件指针位置） q IM
private void write_nPos() v~"Ef_`
{ k6@b|
try{ F>N+<Z
output = new DataOutputStream(new FileOutputStream(tmpFile)); nfX12y_SXL
output.writeInt(nStartPos.length); 2"@Ft()]
for(int i=0;i<nStartPos.length;i++) .Gh%p`<
{ lop uf/U0
// output.writeLong(nPos); B{p4G`$i1
output.writeLong(fileSplitterFetch.nStartPos); Fn!SGX~kx$
output.writeLong(fileSplitterFetch.nEndPos); ibJl;sJ
} 7JI:=yY!>:
output.close(); f=o4I2Y[
} <Nex8fiJ9
catch(IOException e){e.printStackTrace ();} pI>*u ]x
catch(Exception e){e.printStackTrace ();} R:A'&;S
} I!0JG`&
$jG4pPG
b3\B8:XFo|
//读取保存的下载信息（文件指针位置） (/K5!qh
private void read_nPos() D`Gt
{ ^agj4$
try{ =EW3&+Lt
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vX+.e1m
int nCount = input.readInt(); 5`~mqqR5
nStartPos = new long[nCount]; ?E<c[*F05
nEndPos = new long[nCount]; QH~Jy*\+PX
for(int i=0;i<nStartPos.length;i++) .+yW%~0
{ j0FW8!!-g
nStartPos = input.readLong(); R&#tSL
nEndPos = input.readLong(); 7^MX l
} zDDK
input.close(); P16YS8$
} BwxnDeG)
catch(IOException e){e.printStackTrace ();} _A 2Lv]vfV
catch(Exception e){e.printStackTrace ();} V^n0GJNo
} JrDHRIkgm
QU/fT_ORw
E-fr}R}
private void processErrorCode(int nErrorCode) QHzgy?
{ 2n|CD|V$ux
System.err.println("Error Code : " + nErrorCode); DyfsTx
} Mra35
QU T"z'
O*G1 QX
//停止文件下载 ]p]UTCo!'
public void siteStop() Hx %$X
{ !>n|c$=;qk
bStop = true; #Fs|f3-@
for(int i=0;i<nStartPos.length;i++) "MnSJ2
fileSplitterFetch.splitterStop(); YT=eVg53
g9KTn4
aMTFW_w
} ^Kqf~yS%
} Au.:OeJm
//负责部分文件的抓取 eA=WGy@IcN
**FileSplitterFetch.java YEv Lhh
*/ #`ls)-`7
package NetFox; _KN/@(+F
m`6VKp{YD
[i7YVwG4
import java.io.*; qu~X.pW
import java.net.*; zizk7<?L.
lY'N4x7n
oNM?y:O
public class FileSplitterFetch extends Thread { }`o?/!X
p|qyTeg
;YyXT"6/p
String sURL; //File URL KX3KM!*
long nStartPos; //File Snippet Start Position `8:K[gp
long nEndPos; //File Snippet End Position s-rfS7;
int nThreadID; //Thread's ID =X1?_~}
boolean bDownOver = false; //Downing is over jL>:>r
boolean bStop = false; //Stop identical 1] #9
FileAccessI fileAccessI = null; //File Access interface K |*5Kwi
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cozXb$bBY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _xrwu;o0}
{ ,9of(T(~
this.sURL = sURL; rzeLx Wt
this.nStartPos = nStart; /ty?<24ko
this.nEndPos = nEnd; B,vOsa"x6`
nThreadID = id; :%X Ls,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 S8vV!xO
} UE :HMn6
XOy2lJ/
w%a8XnW]1
public void run() ~/-eyxLTm
{ -rSIBc:$8
while(nStartPos < nEndPos && !bStop) #0"~G][#
{ +(?>-3_z
UBZ9A
>#(n"RCHf
try{ g|%L"-%gJ
URL url = new URL(sURL); C#Bz>2;#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d]wD[]
httpConnection.setRequestProperty("User-Agent","NetFox"); PmX2[7
String sProperty = "bytes="+nStartPos+"-"; sL^yB
httpConnection.setRequestProperty("RANGE",sProperty); U|@V 74
Utility.log(sProperty); h7yqk4'Lq
Ev9>@~^
}-DE`c
InputStream input = httpConnection.getInputStream(); izZ=d5+K
//logResponseHead(httpConnection); D'_Bz8H!p
h|;qG)f^
{i [y9
byte[] b = new byte[1024]; %.HJK
int nRead; zsXpA0~3s
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E JK0
{ #8h;Bj
nStartPos += fileAccessI.write(b,0,nRead); r8/l P}(F
//if(nThreadID == 1) c EnkU]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FjFMR 63
} BR5BJX
LT@OWH
x/fX`y|(}*
Utility.log("Thread " + nThreadID + " is over!"); ;_?MX/w|&
bDownOver = true; !>$4]FkV
//nPos = fileAccessI.write (b,0,nRead); {+.r5py
} |L6&Gf]#5
catch(Exception e){e.printStackTrace ();} S:bC[}
} 1Sz A3c
} :t("L-GPW
c64v,Hj9
,'fxIO
//打印回应的头信息 3=0E!e
public void logResponseHead(HttpURLConnection con) K^l:MxO-X
{ Ms^dRe)
for(int i=1;;i++) mpw~hW0-
{ 39i9wrP
String header=con.getHeaderFieldKey(i); ^jE8+h
if(header!=null) W"q@Qa`Bm
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *OjKcs
Utility.log(header+" : "+con.getHeaderField(header)); 4Xj4|Rw%
else GW^,g@%C
break; Orn0Zpp<z
} ]T:;Vo
} 1bnBji
J^#:qk
]< l6s
public void splitterStop() ,m3e?j@;r
{ PmpNAVE'
bStop = true; z+{,WHjo
} iBg3mc@OO
uQ1@b-e`5
o{:xp r=(
} |*5 =_vF
OhZgcUqQ8
u+m,b76
/* :mppv8bh
**FileAccess.java -Z-f1.Dm5
*//文件访问(定位，写) )u%je~Vw
package NetFox; ~&dyRtW4
import java.io.*; feM6K!fL`
bUwn}_7b
?%tMohL
public class FileAccessI implements Serializable{ 2B0W~x2=
/phX'xp
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -Apc$0ZsN
RandomAccessFile oSavedFile; 7cDU2l
long nPos; op2Of<{h
F9"w6;hh
Ex amD">T
public FileAccessI() throws IOException Uu s.
{ /^SAC%PD
this("",0); S[3iA~)Z-
} XN=67f$Hw
,_.I\EY[
}Db[ 4
public FileAccessI(String sName,long nPos) throws IOException 3g'S\G@
{ s8"8y`u
oSavedFile = new RandomAccessFile(sName,"rw"); {P%9
this.nPos = nPos; u7%D6W~m0
oSavedFile.seek(nPos); IY'=DePd
} zG }?
f"G-
CvSIV7zYo
public synchronized int write(byte[] b,int nStart,int nLen) 8`>h}Q$
{ 5zJj]A
int n = -1; ^FmU_Q0
try{ >eQr<-8
oSavedFile.write(b,nStart,nLen); ^|~mlY@w
n = nLen; H<hVTc{K
} !3n)|~r;K
catch(IOException e) 5@IB39
{ b \KL;H/
e.printStackTrace (); }U~6^2 .,
} ?liK\C2Z<
lz#GbXn.
V]OmfPve
return n; u-Ddq~;|
} hd\gH^wk
*K!|@h{60
/n~\\9#3
} _/8FRkx
:bV mgLgG
EF7+ *Q9
/* {^mNJ
**SiteInfoBean.java z?/1Kj}xG
*/ omO S=d!o
package NetFox; FuG4F
.;y#
'FlJpA}
public class SiteInfoBean { 6=4wp?
El_wdbbT
nkxzk$
private String sSiteURL; //Site's URL Hgeg@RP Q
private String sFilePath; //Saved File's Path ORGD
private String sFileName; //Saved File's Name >z;[2n'
private int nSplitter; //Count of Splited Downloading File +d+@u)6
w\54j)rb
P./V6i<:
public SiteInfoBean() h5%<+D<
{//nSplitter的缺省值为5 +;$oJJ
//default value of nSplitter is 5 O ,rwP
this("","","",5); +a&p$\
} /kL$4CA
5$DHn]
q"O.Cbk
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) />¬$>
{ B]m@:|Q
sSiteURL= sURL; 4c oJRqf=
sFilePath = sPath; U~h'*nV&
sFileName = sName; GoA4f3
this.nSplitter = nSpiltter; 3G.5724,
:tIC~GG]_)
IDkWGh
} *n]7
2LrJ>Mi
~$'\L
public String getSSiteURL() Fc~'TBf,,`
{ `U+l?S^$
return sSiteURL; RZM"~ 0
} }kw/W#)J
4h5g'!9-g
f|^dD`
public void setSSiteURL(String value) 5MFxo63
{ ,jXM3?>B
sSiteURL = value; O^/Maa/D1
} I1[g&9,
A7(hw~+@
u` oq(?|
public String getSFilePath() Fk(JSiU
{ ?)bS['^1)
return sFilePath; |mdi]TL
} D9`0Dr}/2
kb[P\cRa
iA8U Yd3Q
public void setSFilePath(String value) 0sI1GhVR
{ KIR'$ 6pn~
sFilePath = value; M?=;JJ:
} *),8PoT
OB[o2G<0
66^ycZCH
public String getSFileName() TKk-;Y=N
{ qwIa?!8o
return sFileName; J=pztASt
} i)#s.6.D>
LL|7rS|o
;7N Z<k
public void setSFileName(String value) AuR$g7z
{ d Le-nF
sFileName = value; .{;Y'Zc14S
} RI68%ZoL
sXd8rj:o
rr#K"SP
public int getNSplitter() ;raN
{ B||;'
return nSplitter; .VTy[|o
} K}6dg<
Cy*|&=>j
l>Ub!^;
public void setNSplitter(int nCount) )lJao
{ (`? y2n)~W
nSplitter = nCount; E*#]**
} ?$e9<lsQq)
} VUI|.76g
6a;v&5
nFe%vu8a
/* %,hV[[@.
**Utility.java aR,}W\6M
*/ TYI7<-Mp:[
package NetFox; !QDQ_
# O4gg
JHf
public class Utility { )5|I_PXB
='TE,et@d
U^qt6$bK
public Utility() S1/`th
{ "R8KQj
Hcc"b0>}{
%Th>C2\
} @iEA:?9uX
4A9{=~nwT
//线程睡眠 Xn~I=Ml d
public static void sleep(int nSecond) $.Q$`/dF
{ zni)<fmju
try{ Isx#9C
Thread.sleep(nSecond); 191&_*Xb
} PQ@L+],C
catch(Exception e) ORu2V#Z[
{ -{`@=U
e.printStackTrace (); |Yq$sU
} [!%![E
} BL 3gKx.'
a,78l@d(
//日志 Jv.UQ
public static void log(String sMsg) #z1H8CFL"
{ )"+(butI&
System.err.println(sMsg); !?^b[ nC%
} 2>*%q%81
e[Abp~@M1
=TqQbadp
public static void log(int sMsg) -48vJR*tC
{ vP+@z-O
System.err.println(sMsg); n]dL?BJ
} pH`44KAuM
} @-OnHE
KRjV}\}
4e;QiTj
/* =}PdH`S
**TestMethod.java BcD&sQ2F
*/ #$3yz'"QF
package NetFox; G<M:Ak+~
s&GJW@ |
udeoW-_
public class TestMethod { i|1^+;
xG;-bJu
D/h/Y) Y
public TestMethod() Jjl`_X$CB
{ ///xx/weblogic60b2_win.exe )Fb>8<%
try{ 4[r/}/iGo
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); fr!Pj(Q1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Py{<bd
SiteFileFetch fileFetch = new SiteFileFetch(bean); (MHAJ]Rx
fileFetch.start(); d6i6hcQE
} f{0F|w<gf
catch(Exception e){e.printStackTrace ();} GUQ{r!S
h=_mNG>R)
<w\:<5e'
} #Wu*3&a]yU
k<+0o))
S.!UPkWH
public static void main(String[] args) :$+-3_oLMQ
{ @|'5n
new TestMethod(); wW>)(&!F
} w\}?(uO
} >[6{LAe~hp
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