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)); 4n3QW%#
} 2IjqTL
for(int i=0;i<nEndPos.length-1;i++) hN\E8"To
{ tB(Q-c
nEndPos = nStartPos[i+1]; !c6lP'U
} VPN@q<BV
nEndPos[nEndPos.length-1] = nFileLength; 7/Lbs
} [-6j4D
} qgZ(o@\
!YJdi~q
](MXP,R
//启动子线程 @Jm$<E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fvit+
for(int i=0;i<nStartPos.length;i++) dUO~dV1
{ *qOo,e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ix:aHl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8.k"kXU@n
nStartPos,nEndPos,i); IR/0gP
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0@AK
fileSplitterFetch.start(); (59<Zo
} yv3myaS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &)s A(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1pzU=!R?-O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D%^EG8i n.
nEndPos = " + nFileLength); Q|5wz]!5Y(
// fileSplitterFetch[nPos.length-1].start(); (|U+(~PJ
Y}1|/6eJ
&OI=rvDmo
//等待子线程结束 ][G<CO`k
//int count = 0; _"WQi}Mm
//是否结束while循环 `n^jU92
boolean breakWhile = false; Kq{s^G
f7s]:n*Ih
P\2QH@p@t
while(!bStop) q,:\i+>K*
{ 9,y&?GLP
write_nPos(); 42m`7uQ
Utility.sleep(500); 8 6L&u:o:
breakWhile = true; *EV]8
_^a.kF
h@W}xT
for(int i=0;i<nStartPos.length;i++) |d%Dw^
{ ;7m>40W
if(!fileSplitterFetch.bDownOver) =z=Guvcn`
{ kOtC(\]5
breakWhile = false; tOspDPSXX
break; gVG :z_6
} hJd#Gc~*M
} ~Zj?%4
if(breakWhile) h+Q==
break; k.lnG5e
Q;aZpi-E"
J=\Y4- "
//count++; %{HqF>=~
//if(count>4) /@wm?ft6Gk
// siteStop(); wh*OD
} q1?2 U<
~(%G;fZ?x
pM#:OlqC
System.err.println("文件下载结束！"); W1:o2 C7
} ,Y`C7Px
catch(Exception e){e.printStackTrace ();} &UzZE17R
} {g @ *jo&
dvL'>'g
<|2_1[,sl
//获得文件长度 Kjf#uU.7
public long getFileSize() Np/[MC
{ iOJgZuP
int nFileLength = -1; pnqjATGU
try{ &rNXn?>b
URL url = new URL(siteInfoBean.getSSiteURL()); I)Y$?"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |Zt=8}di
httpConnection.setRequestProperty("User-Agent","NetFox"); jM7}LV1Ck
W B!$qie\
(yXVp2k
int responseCode=httpConnection.getResponseCode(); !4 hs9b
if(responseCode>=400) @x=CMF15
{ "n8_Ag@r
processErrorCode(responseCode); ;l`8w3fDt
return -2; //-2 represent access is error ~Yr.0i.W
} (>8fcQUBb
N@A#e/8
F8=6!Qj
String sHeader; G4RsH/
Ko%rB+d
o&CvjE
for(int i=1;;i++) Wc]Fg9E
{ ~Snw':
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qy-BZ%3
//Utility.log(in.readLine()); `nizGg~1
sHeader=httpConnection.getHeaderFieldKey(i); mYy3KqYu
if(sHeader!=null) d->b9
{ UWusSi3+LG
if(sHeader.equals("Content-Length")) O!j@8~='
{ p[/n[@<8=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XBr>K>(
break; z?gJHN<
} Zv-6H*zM6
} k,@1rOf
else N9*$'
break; tP:xx2N_
} DX!$k[
} k[zf`x^
catch(IOException e){e.printStackTrace ();} ?.Kl/8ml
catch(Exception e){e.printStackTrace ();} >eEf|tKO
4o=G) KO{
X'u`\<&W
Utility.log(nFileLength); |BW956fBU
}YSH8d
Qy$QOtrv
return nFileLength; PAc~p8S
} MRC5c:(
-!}1{
1u`Z?S(
//保存下载信息（文件指针位置） S\X_!|
private void write_nPos() @=,J6
{ $"UAJ-
try{ H{}6`;W
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]':C~-RV{
output.writeInt(nStartPos.length); jxoEOEA
for(int i=0;i<nStartPos.length;i++) 9z-"JnM
{ pTN_6=Y"
// output.writeLong(nPos); zCQv:.0L
output.writeLong(fileSplitterFetch.nStartPos); TxiJ?sDh*
output.writeLong(fileSplitterFetch.nEndPos); DBv5Og
} Th8Q~*v
output.close(); pE`(kD
} \UC4ai2MK
catch(IOException e){e.printStackTrace ();} 1rKR=To
catch(Exception e){e.printStackTrace ();} .DX#:?@4@Y
} +amvQ];?Q8
awawq9)Y
O@$hG8:
//读取保存的下载信息（文件指针位置） 3gM{lS}h#
private void read_nPos() qJK^i.e
{ vd;wQ
try{ 49#-\=<gt
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~q4y'dBy*
int nCount = input.readInt(); dqkkA/1
nStartPos = new long[nCount]; |/s.PNP2
nEndPos = new long[nCount]; Mfz5:'
for(int i=0;i<nStartPos.length;i++) $wN.~"T
{ )N=wJN1
nStartPos = input.readLong(); ?y '.sQ
nEndPos = input.readLong(); vbFAS:Y:+
} |'J3"am'
input.close(); i3GvTg-X
} iIT<{m&`
catch(IOException e){e.printStackTrace ();} "2h#inS
catch(Exception e){e.printStackTrace ();} lfKknp#B/O
} !of7]s
jab]!eY
K4rr.f6
private void processErrorCode(int nErrorCode) t.zSJ|T_&O
{ fg9sZ%67]\
System.err.println("Error Code : " + nErrorCode); _I!Xr!!)a0
} 2Fh_
&p%,+|
jmb\eOq+~V
//停止文件下载 63f/-64?7
public void siteStop() 2ReulL8j
{ d}G?iX;c}
bStop = true; U!'lc}5
for(int i=0;i<nStartPos.length;i++) %MIu;u FR
fileSplitterFetch.splitterStop(); /}VQzF
she`_'?5
+-Dd*yD6<
} c`>\R<Z ]
} nqH^%/7)A@
//负责部分文件的抓取 dOhV`8l
**FileSplitterFetch.java M{S7ia"s
*/ OBZ|W**N"
package NetFox; /X:lt^?%I
@U)'UrNr~
6M6QMg^
import java.io.*; JC#@sJ4az)
import java.net.*; Dux`BKl
U%4g:s
-Z Z$ 1E
public class FileSplitterFetch extends Thread { X1-s,[j'
?yz%r`;r
\w:u&6,0O
String sURL; //File URL (kHR$8GFM
long nStartPos; //File Snippet Start Position j@ "`!uPz
long nEndPos; //File Snippet End Position bXW)n<y
int nThreadID; //Thread's ID J.&q[
boolean bDownOver = false; //Downing is over sH]AB=_
boolean bStop = false; //Stop identical *HC8kD a%$
FileAccessI fileAccessI = null; //File Access interface e%P;Jj476
{, |"Rpd
H )}WWXK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bDkE*4SRX
{ 8N`$7^^
this.sURL = sURL; UVLcR
this.nStartPos = nStart; =?lT&|"
this.nEndPos = nEnd; 5B2,=?+o
nThreadID = id; Yyo|W;a]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zbR.Lb
} d3$<|mG$
4Rm3'Ch
W>~%6K>p
public void run() 7L]?)2=
{ $7r wara
while(nStartPos < nEndPos && !bStop) `SW " RLS3
{ KCFwO'
mx[^LaR>v
qh'BrYu*
try{ JA}'d7yEa
URL url = new URL(sURL); [E^X=+Jnz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g-^m\>B
httpConnection.setRequestProperty("User-Agent","NetFox"); jysV%q 3
String sProperty = "bytes="+nStartPos+"-"; Dmi;# WY
httpConnection.setRequestProperty("RANGE",sProperty); ;Y'\:
Utility.log(sProperty); </Id';|v
n96gDH*
s`J=:>9*
InputStream input = httpConnection.getInputStream(); e^GW[lT
//logResponseHead(httpConnection); \,EPsQV0?
VqrMi *W6
]Yu+M3Fq
byte[] b = new byte[1024]; _HK&KY
int nRead; acZHb[w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l!y _P
{ M;Rw]M
nStartPos += fileAccessI.write(b,0,nRead); ]*@$%iCPE
//if(nThreadID == 1) 9O Q4\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ib\G{$r
} =QfKDA
aX%Zuyny
?>8zU;Aj
Utility.log("Thread " + nThreadID + " is over!"); I`TD*D
bDownOver = true; !S!03|
//nPos = fileAccessI.write (b,0,nRead); EAB+kY
} K)+l6Q
catch(Exception e){e.printStackTrace ();} ?GarD3#A
} #<PdZl R
} 5Nb_K`Vp*
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5)7mjyo%
//打印回应的头信息 /vDF<HVzm
public void logResponseHead(HttpURLConnection con) S7/v,E
{ 1hyah.i]Y
for(int i=1;;i++) Q/n.T0Z^
{ I 6YT|R
String header=con.getHeaderFieldKey(i); )T5h\ZO`;
if(header!=null) ;"^9L
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .^S78hr]n
Utility.log(header+" : "+con.getHeaderField(header)); F\R}no5C
else mv?H]i`N
break; y7-:l u$9
} J\+gd%
} b6Hk20+B;
B9DxV>mr\r
;cn.s,
public void splitterStop() GKhwn&qCKb
{ ^6oqq[$
bStop = true; s~ZFVi-i
} .b`P!
&n.uNe
5{0>7c|.
} eKz~viM'
'F?Znd2L
!s*''v*
/* 0r ; nz]'
**FileAccess.java FqxOHovE
*//文件访问(定位，写) 1GE%5
package NetFox; nj0AO0
import java.io.*; k3[h'.ps
6xIYg^
SzlfA%4+GR
public class FileAccessI implements Serializable{ 64']F1p0
!TL}~D:J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o;>3z*9?3
RandomAccessFile oSavedFile; 0,$-)SkT
long nPos; rY?F6'}
>MWpYp
K_|~3g
public FileAccessI() throws IOException yLO &(Mb
{ :@`(}5F4
this("",0); s|j<b#<xQ
} &9_\E{o%]
';\gR/L
<GgtP55
public FileAccessI(String sName,long nPos) throws IOException u?3NBc$~A
{ AJ` v
oSavedFile = new RandomAccessFile(sName,"rw"); AV 5\W}
this.nPos = nPos; '#i]SU&*
oSavedFile.seek(nPos); AOx3QgC^NO
} FT/5 _1i
o-=d|dWG
_#D\*0J
public synchronized int write(byte[] b,int nStart,int nLen) d<Q+D1
{ iynS4]`U
int n = -1; EKd3$(^
try{ hJo^Wo
oSavedFile.write(b,nStart,nLen); VUC <0WV
n = nLen; ^GrkIh0nL
} E'^]zW=9
catch(IOException e) #O9*$eMw
{ + lB+|yJ+
e.printStackTrace (); +#uNQ`1v
} )*K<;WIWH
+:]Aqyc\
EPe]-C`
return n; NVc!g
} X'#$e{
B.mbKntK)R
aDl, K;GL
} g{W6a2
ZE8/ m")
&[ u6oAR
/* R=amKLD?
**SiteInfoBean.java 4-+ozC{
*/ #A/]Vs$
package NetFox; t&9as}
RCh$j&Tn
=,d* {m~A
public class SiteInfoBean { Y%)h)El
|J<pLz
XiRT|%j
private String sSiteURL; //Site's URL C9mzg
private String sFilePath; //Saved File's Path ;o)=XEh8P
private String sFileName; //Saved File's Name ]]uzl0LH
private int nSplitter; //Count of Splited Downloading File (~7m"?
Z<N&UFw7QJ
P~\a)Szy
public SiteInfoBean() ].-J.
{//nSplitter的缺省值为5 up&NCX
//default value of nSplitter is 5 G/fP(o-Wd
this("","","",5); c+8>EU AW
} Oj"pj:fB
!u53 3
1<W4>~,wj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,qe]fo >
{ 5BU%%fBJ.
sSiteURL= sURL; Ig02M_
sFilePath = sPath; \,l.p_<
sFileName = sName; 8|5Gv
this.nSplitter = nSpiltter; oEenm\ZI
Txt%nzIu
)l#%.Z9
} :Hzz{'
(:?5 i`
t+3
public String getSSiteURL() nIyROhZ
{ lrs0^@.+
return sSiteURL; ;]gsJ9FK<
} :F^$"~(,
~KAp\!,
d; mmM\3]
public void setSSiteURL(String value) 8! H8[J
{ @],6SKbG6
sSiteURL = value; :BL'>V
} <JL\?)}n
s-,=e
`Di ^6UK(
public String getSFilePath() C#U<k0R
{ z^gQ\\,4
return sFilePath; `1fJ:b/M
} {PODisl>\D
W;Ud<7<;Z
j-lSFTo
public void setSFilePath(String value) Rwc[:6;fn
{ I&TTr7
sFilePath = value; JrCf,?L^
} L_THU4^j
mL:m;>JJ n
DKy>]Hca
public String getSFileName() c*x J=Gz6d
{ QKp+;$SE'
return sFileName; +cz"`T`X 2
} .cg=
r5MxjuOB1
3>-[B`dD(
public void setSFileName(String value) y|q@;*rGNa
{ Rk($lW)
sFileName = value; zmrQf/y{R
} Js\-['`
9J~:m$.
5^/,aI
public int getNSplitter() E4sn[DO
{ J)9 AnGWe
return nSplitter; "/ tUA\=j
} 9W{,=.%MX$
CfPXn0I
V";mWws+?#
public void setNSplitter(int nCount) )KSisEL
{ :/o C:z\h
nSplitter = nCount; { 1+Cw?1d
} K0tV'Ml#"
} i\t753<Ys
xS=_yO9-
<8u>_o6
/* 0JmFQ^g(
**Utility.java R%>jJ[4\[
*/ b8rp8'M)
package NetFox; W|)GV0YM
oN *SRaAp
kQ@gO[hS
public class Utility { 9@:BK;Fi
QCeMKjCmY
H@K#|A=a
public Utility() 'e}uvbK
{ =yl4zQmg$
F(#haJ$>
z%OuI 8"'
} R=!kbBK>\
Q;4}gUmI$
//线程睡眠 fv|]= e
public static void sleep(int nSecond) :]vA2
{ K@B" ]6
try{ <^d!Vzr]
Thread.sleep(nSecond); cNe0x2Z$?
} h,^BC^VU9-
catch(Exception e) u3U4UK
{ 30D:ZmlY
e.printStackTrace (); !n|#|.0m
} EJ1Bq>u7
} ARPKzF`Wq
10mK}HT>4B
//日志 }7K@e;YUg
public static void log(String sMsg) k/%#>
{ 59V#FWe-
System.err.println(sMsg); OkLz^R?d
} 3)}(M
W%TQYR
+wipfL~&S
public static void log(int sMsg) 538fK9[
{ 2b5#PcKa
System.err.println(sMsg); +a|"{
} zJ5hvDmC
} vkJ)FEar
M)L/d_4ka
BWWq4mdb{
/* hw;0t,1
**TestMethod.java 'iJDWxCD
*/ =/[ltUKs:a
package NetFox; JjQ8|En
T'E] i!$
2+z1h^)W
public class TestMethod { )B6# A0
1!vPc93 $$
R,%_deV\(
public TestMethod() YydA6IK4
{ ///xx/weblogic60b2_win.exe ?]^zD k@~
try{ @<2d8ed
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R~)ybf{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u#1%P5r&X
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]Kv q |}=
fileFetch.start(); k}GjD2m
} Y,C=@t@_
catch(Exception e){e.printStackTrace ();} Q $]YD pCM
y,Jh@n';|
k0L] R5W
} %Uy%kN_&
Y(_KizBY
P|N2R5(>T
public static void main(String[] args) Jy]Id*u9
{ 6JhMkB^h
new TestMethod(); @D)Z{=>{=5
} L7]]ZAH!1
} pE2QnNr'
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