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)); z8g=;><
} btUq
for(int i=0;i<nEndPos.length-1;i++) jVX._bEGX
{ s0gJ f[
nEndPos = nStartPos[i+1]; n)tU9@4Np
} B:e.gtM5
nEndPos[nEndPos.length-1] = nFileLength; vAi"$e
} NV:>a
} JR/W9i
ktN%!Mh\
kclp}
//启动子线程 XlRw Z/Wc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; W7%p^;ZQ$
for(int i=0;i<nStartPos.length;i++) HpW"lYW4
{ T48BRVX-F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u06tDJ[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xy2\'kS`G
nStartPos,nEndPos,i); {V.Wk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z/xV\Ggx
fileSplitterFetch.start(); MO[c0n%
} /^d. &@*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AeN 3<|RN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W5pn;u- sz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *:?QB8YJ
nEndPos = " + nFileLength); *f{7
// fileSplitterFetch[nPos.length-1].start(); g+igxC}2z
/d[Mss
7`Qde!+C
//等待子线程结束 >+L7k^[,0
//int count = 0; |Es0[cU
//是否结束while循环 U> W|(Y
boolean breakWhile = false; (viWY
=ntftSH
j(&GVy^;?
while(!bStop) HB%K|&!+
{ QQ*gFP.Ao
write_nPos(); 6j_ 678
Utility.sleep(500); ol50d73B
breakWhile = true; KrS
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E\ tL
for(int i=0;i<nStartPos.length;i++) Z?-;.G*
{ [9LxhPi
if(!fileSplitterFetch.bDownOver) 8IeI0f"l)
{ '[%jjUU
breakWhile = false; 1bd$XnU
break; dQ,Q+ON>
} CdZnD#F2
} 1y7y0V
if(breakWhile) X|,["Az 8
break; Pv~:gP
)5U!>,fT
L"4]Tm>zq
//count++; v3-5"q!Sq
//if(count>4) &i)helXs]
// siteStop(); -=5EbNPwG
} TM)u?t+[
X2LV&oi
su}&".e^
System.err.println("文件下载结束！"); Z A[)
} 00"CC
catch(Exception e){e.printStackTrace ();} /\d(c/,4
} rjXnDh]MC
*u}'}jC1X
3\1#eK'TK.
//获得文件长度 h 5Hr[E1
public long getFileSize() Sg_O?.r
{ 9YAM#LBTWi
int nFileLength = -1; lVP |W:~K
try{ &m'?*O |
URL url = new URL(siteInfoBean.getSSiteURL()); w#sq'vo4%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f$vwuW
httpConnection.setRequestProperty("User-Agent","NetFox"); r|<6Aae&
eIsT!V"7
9976H\{
int responseCode=httpConnection.getResponseCode(); 7N| AA^I
if(responseCode>=400) pziq0
{ Vu%n&uF
processErrorCode(responseCode); G?R_aPP
return -2; //-2 represent access is error 0t+])>
} f\ 'T_
pcnl0o~
[z2eCH
String sHeader; vTHq)C.7G
eSn$k:\W
3-iD.IAUm@
for(int i=1;;i++) *,0+RASvq
{ sCkO0dl8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?~Pv3'%d
//Utility.log(in.readLine()); JYQ.EAsr!
sHeader=httpConnection.getHeaderFieldKey(i); Ev{MCu1!6
if(sHeader!=null) <<sE`>)
{ e?P%wqB
if(sHeader.equals("Content-Length")) 57<Di!rt
{ eVx~n(m!}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^&NN]?
break; T<6GcI>A
} ?2ItTrlB
} 7E\g &R.
else M$H`^Pv
break; \E77SO,$
} 5B?i(2&#
} Im+7<3Z
catch(IOException e){e.printStackTrace ();} !b63ik15O~
catch(Exception e){e.printStackTrace ();} X8Fzs!L`
toIYE*ocv=
!W /C[$E
Utility.log(nFileLength); Bzw19S6y
{[P!$ /
M*(H)i;s:w
return nFileLength; \7 Gz\=\LR
} 1O0X-C,wo$
8#l+{`$z
/?P!.!W&
//保存下载信息（文件指针位置） @vt$MiOi
private void write_nPos() ~j"3}wXc5
{ 'fn$'CeM(
try{ WqQU@sA
output = new DataOutputStream(new FileOutputStream(tmpFile)); #w|5jN?
output.writeInt(nStartPos.length); dlR_ckp
for(int i=0;i<nStartPos.length;i++) Zi*%*nX
{ Oyan9~
// output.writeLong(nPos); |IN[uQ
output.writeLong(fileSplitterFetch.nStartPos); d@ (vg
output.writeLong(fileSplitterFetch.nEndPos); QD4:W"i
} Du!._
output.close(); %Kl(>{N
} /[{auUxSX
catch(IOException e){e.printStackTrace ();} I .P6l*$
catch(Exception e){e.printStackTrace ();} NbkK&bz
} ;A"\?i Q
G "brT5:
>f@ G>H)+
//读取保存的下载信息（文件指针位置） y\,f6=%k
private void read_nPos() " #v%36U
{ 3[VNsX
try{ ;7j,MbU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *|KVN&#
int nCount = input.readInt(); x<>YUw8`
nStartPos = new long[nCount]; P)hi||[
nEndPos = new long[nCount]; ;_N5>3C:
for(int i=0;i<nStartPos.length;i++) aq$q ~,E
{ <u0,Fp
nStartPos = input.readLong(); bo>E"<
nEndPos = input.readLong(); 8UM0vNk
} 328L)BmW
input.close(); &d,Wy"WPi
} `0@z"D5c
catch(IOException e){e.printStackTrace ();} q3+8]-9|5
catch(Exception e){e.printStackTrace ();} FmD +8=
} T1zi0fa'
MI*Sq\-i
taDQ65
private void processErrorCode(int nErrorCode) .iT4-
{ Hi8Y6|y$D
System.err.println("Error Code : " + nErrorCode); %/pc=i|+
} ArXl=s';s4
-Qb0:]sV#
^P$7A]!
//停止文件下载 zPE$
public void siteStop() }-nU3{1
{ B9#;-QO
bStop = true; d.r Y-k
for(int i=0;i<nStartPos.length;i++) qqvF-mDN
fileSplitterFetch.splitterStop(); S>t>6&A
"+h/-2rA
yU_9a[$V
} T*+A.G@L"
} D^?_"wjW
//负责部分文件的抓取 -oh7d$~
**FileSplitterFetch.java "b%FmM
*/ m~>@BCn;
package NetFox; sE9Ckc5
1;&T^Gdj
PGX+p+wB
import java.io.*; +tUQ
import java.net.*; c-*2dV[@
z<<Tk.65
vr4S9`,
public class FileSplitterFetch extends Thread { _yVPpA[a
!^v\^Fc
$E.XOpl&I
String sURL; //File URL +)gB9DoK
long nStartPos; //File Snippet Start Position jBRPR R0
long nEndPos; //File Snippet End Position xZ+]QDKC
int nThreadID; //Thread's ID r/PKrw sC
boolean bDownOver = false; //Downing is over . #U}q 7X
boolean bStop = false; //Stop identical *Hunp Y
FileAccessI fileAccessI = null; //File Access interface M[s\E4l:t
o;QZe&
)`Ed_F}k
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'C~9]Y].
{ mHs:t{q
this.sURL = sURL; x+:zq<0|
this.nStartPos = nStart; _9kIRmT{
this.nEndPos = nEnd; t?3BCm$Mi
nThreadID = id; TQ'e
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ikHOqJ-,m
} 98UlNP
)4uq iA6
QJSr:dP4dG
public void run() 9p*-?kPb
{ I?M@5u
while(nStartPos < nEndPos && !bStop) q[c Etp28h
{ ,sI35I J
NvHN -^2
5~l2!PY
try{ IG|\:Xz
URL url = new URL(sURL); W~NYU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,` o+ ?
httpConnection.setRequestProperty("User-Agent","NetFox"); n7DLJ`ho{
String sProperty = "bytes="+nStartPos+"-"; / O)6iJ
httpConnection.setRequestProperty("RANGE",sProperty); e1^l.>2d6
Utility.log(sProperty); or.\)(m#(
0;cuX@A/a?
}Vl^EAR
InputStream input = httpConnection.getInputStream(); g;G5 r&T
//logResponseHead(httpConnection); )X%oXc&C|
LyP`{_"CM
3EOyq^I%
byte[] b = new byte[1024]; FmI;lVF0j
int nRead; $5L(gn[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B5`;MQJ
{ b1)\Zi
nStartPos += fileAccessI.write(b,0,nRead); wY`#$)O0*
//if(nThreadID == 1) OG}KqG!n
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]]y[t|6
} [q"NU&SX
QgZJ`G--
s41adw>
Utility.log("Thread " + nThreadID + " is over!"); rKIRNc#d
bDownOver = true; U8[Qw}T P
//nPos = fileAccessI.write (b,0,nRead); }4KW@L[g
} dEET}s\
catch(Exception e){e.printStackTrace ();} mu>] 9ZW
} r=\P!`{5
} @,Jb7V<
y/\ZAtnLo
6sy,A~e
//打印回应的头信息 Xi+n`T'i
public void logResponseHead(HttpURLConnection con) c(&AnIlS
{ SwJHgZ&
for(int i=1;;i++) )f[C[Rd
{ Q@Dkl F
String header=con.getHeaderFieldKey(i); ==`Pb
if(header!=null) c/RT0xql*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 07Y_^d
Utility.log(header+" : "+con.getHeaderField(header)); ZQ|gt*
else Z9f/-|r5
break; kyu2)L2u
} "$P'Wv
} q|Fjm]AF
DZ2Fl>7
S*s:4uf
public void splitterStop() 4v>o%
{ $E@ouX?
bStop = true; &t_A0z
} X98#QR#m
h,~tXj
6+?wnp-
} z2v<a{e
}1,'rmT
YQx?* gZS
/* {dBB{.hX
**FileAccess.java $8Ig&k|~8
*//文件访问(定位，写) y]7%$* <
package NetFox; T:6K?$y?
import java.io.*; R~$hWu}}
J ZA*{n2
i`R(7Z
public class FileAccessI implements Serializable{ <5M_EJp
L,WkJe3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %uj[`
RandomAccessFile oSavedFile; el}hcAY/RP
long nPos; Q7L)f71i
*!i,?vn
<o~t$TH
public FileAccessI() throws IOException MCM/=M'y
{ ,}u,)7
this("",0); \zBd<H4S:
} VZHr-z$6n
)dqR<)
>CH
public FileAccessI(String sName,long nPos) throws IOException hN[X 1*
{ hI*`>9l
oSavedFile = new RandomAccessFile(sName,"rw"); ]9#CVv[rq
this.nPos = nPos; bBy'v/
oSavedFile.seek(nPos); 1k$2LQ
} ccRlql(
3xP~~j;7
Y$>+U
public synchronized int write(byte[] b,int nStart,int nLen) jiqi!*
{ '^8g9E.4K
int n = -1; 5QKRI)XpZ
try{ [?A&xqO3
oSavedFile.write(b,nStart,nLen); c^rC8E
n = nLen; Ob7zu"zr
} z'?SRK5+
catch(IOException e) 6BUBk>A`
{ @<|6{N<
e.printStackTrace (); JvKO $^
} 6euR'd^Qi
fDL3:%D
_MGNKA6JI
return n; ]gb _Nv
} ,<7"K&
)gr}<}X)B
C\y[&egww
} 4s[`yV
B.V?s,U
joxS+P5#
/* su,`q
**SiteInfoBean.java Ga]47pQ"F
*/ 9 aY'0wa
package NetFox; ~o:rM/!Ba
bjuYA/w<
>?^~s(t
public class SiteInfoBean { 7ESN!
qsD?dHi7
G%xb0%oi]%
private String sSiteURL; //Site's URL \El|U#$u'
private String sFilePath; //Saved File's Path XPar_8I
private String sFileName; //Saved File's Name gmXy>{T
private int nSplitter; //Count of Splited Downloading File j kSc&
W/#KX}4
Rbx97(wK
public SiteInfoBean() ,lrYl!,
{//nSplitter的缺省值为5 ,h3269$J
//default value of nSplitter is 5 H|grbTv,
this("","","",5); `6|i&w:b
} D."cQ<sxpN
suA+8}o]
pw0Px
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q>Q:X3
{ 6Hc H'nmeN
sSiteURL= sURL; H+S~ bzz
sFilePath = sPath; l[tY,Y:4qO
sFileName = sName; Dm7Y#)%8
this.nSplitter = nSpiltter; 5LDQ^n
it(LphB8
A~qW.
} CnxK+1n l
3$GY,B
_<u8%\
public String getSSiteURL() vpZu.#5c
{ 1"8Z y6t
return sSiteURL; `4q5CJ2
} *ah>-}-
v_y!Oh?EG
{Q{lb(6Ba
public void setSSiteURL(String value) vp"%IW
{ KC@k9e
sSiteURL = value; W,QnU d'N
} -9=M9}eDF
L9E;Uii0
l=oN X"l=
public String getSFilePath() ZA*b9W
{ 6Cz7A
return sFilePath; <C7M";54-
} 5*s1qA0^
4M;sD;3
tQNk=}VR7r
public void setSFilePath(String value) Tns?mQ
{ @rnp- +kq
sFilePath = value; jxRF"GD
} C><<0VhU
*(?U
:z0s*,QH
public String getSFileName() LydbP17K}
{ ek<PISlci
return sFileName; hQgk.$g
} FRl3\ZDqrb
'hwV
U%mkhWn
public void setSFileName(String value) e%P+KX
{ 6F|Hg2tpz
sFileName = value; DFt=%aV[
} _hAj2%SL
0EL\Hd
c8bca`
public int getNSplitter() 7\7Brw4
{ yt/20a
return nSplitter; 6%\7.h
} SREDM
Tf&f`/
`jD8(}_
public void setNSplitter(int nCount) /|4Q9=
{ OqfhCNAY
nSplitter = nCount; Bo\a
} WUE)SVf
} ^kCk^D-Gz
-XS+Uv
KKx&UKjV
/* e3yorQ][
**Utility.java 5PPPd-'Z_
*/ _H~pH7WU
package NetFox; @Og\SZhn
@{J!6YGh
N.fQ7z=Z(M
public class Utility { Hrd5p+j
OPvj{Dv$0
jRv;D#Hp
public Utility() ?~VWW<lR
{ -Z`(? k
6=Y3(#Ddt
c]AKeq]
} mhHA!:Y
8! |.H p
//线程睡眠 kcq9p2zKv
public static void sleep(int nSecond) Bo](n*i
{ h/0<:eZ*
try{ &y#\1K
Thread.sleep(nSecond); rE1np^z7
} Pi&fwGL
catch(Exception e) #hy5c,}>
{ Dg9--wI}I9
e.printStackTrace (); _Ep{|]:gw
} M-&^
} ct2_N
p?Z+z
//日志 `@fhge
public static void log(String sMsg) ()JYN5
{ 7':5
System.err.println(sMsg); ?YkO+?}+
} u):%5F/
mC{!8WC@k
mFgb_Cd
public static void log(int sMsg) >j(I[_g
{ qHC*$v#.V?
System.err.println(sMsg); SHXa{-
} 0,vj,ic*WX
} :|3"H&FWK
b.mjQ
TRr4`y%
/* zn2"swhq\V
**TestMethod.java >0g`U
*/ J[& 7,}
package NetFox; N8DiEB3~
{Gk}3u/
}6uV]V{
public class TestMethod { E5Snl#Gl\0
n3HCd-z
*hk{q/*Qw
public TestMethod() k2_6<v Z
{ ///xx/weblogic60b2_win.exe MQ9M%>
try{ ,z0~mN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~L\(/[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OVQxZ~uQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); {jx#^n&5R
fileFetch.start(); ,{`o/F/
} 0btmao-
catch(Exception e){e.printStackTrace ();} T0*TTB&b
@ 2%.>0s.
6S! lD=
} m5'__<
2kp|zX(
A3 Rm0
public static void main(String[] args) %4r!7X|O<
{ =XRgT1>e
new TestMethod(); .^9/ 0.g8t
} XDrlJvrPL
} )'K!)?&d
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