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)); l-<3{!
} 22)0zY%\
for(int i=0;i<nEndPos.length-1;i++) !Qv5"_
{ J6)efX)j-p
nEndPos = nStartPos[i+1]; 8%;}LK
} <Jwi~I=^
nEndPos[nEndPos.length-1] = nFileLength; J 6(~>g
} &K5C=]4
} Y%78>-2L
DC?21[60
V*6l6-y~Ih
//启动子线程 l;XU#6{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gHQPhe#n
for(int i=0;i<nStartPos.length;i++) .abyYVrN4?
{ /hm84La
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dV5PhP>6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Tg"'pO
nStartPos,nEndPos,i); ZhhI@_sz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >EBZ$X
fileSplitterFetch.start(); WW//heJe-
} x`]Ofr'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +<pVf%u5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); nGq]$h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B3y?.
nEndPos = " + nFileLength); %*$5!;
// fileSplitterFetch[nPos.length-1].start(); Wyy^gJl
k0H?9Z4k5
NFB*1_m
//等待子线程结束 6N9 c<JC
//int count = 0; ]YCPyc:
//是否结束while循环 W*YxBn4
boolean breakWhile = false; O!:QJ ^8d
-h>Z,-DE6
r0)JUc}Fyq
while(!bStop) ! G*&4V3Mg
{ f=t:[< )
write_nPos(); c*N50%=4
Utility.sleep(500); Iq)(UfaSve
breakWhile = true; @)o0GHNP
xLA~1ZSVJw
}sf YCz
for(int i=0;i<nStartPos.length;i++) )HEfU31IC
{ WHp97S'd
if(!fileSplitterFetch.bDownOver) MQwIPjk8
{ IZO@V1-m
breakWhile = false; D,c!#(v cK
break; 25aNC;J
} 6XdWm
} bRWIDPh
if(breakWhile) t(}/g
break; FXS^^p P
cb+l"FI7
uCw>}3
//count++; RG&I\DTyt
//if(count>4) Dt W*n1Bt
// siteStop(); `&7mHa61
} /r276Q
-7k[Vg?
wAw42{M
System.err.println("文件下载结束！"); 8h@q
} ;xfO16fNk
catch(Exception e){e.printStackTrace ();} 3FFaEl
} 92ZWU2"
Ffnk1/Zy
CK2B
//获得文件长度 y>$1UwQ
public long getFileSize() B1E$v(P3M
{ '0Lov]L
int nFileLength = -1; BYS lKTh
try{ P^"R4T
URL url = new URL(siteInfoBean.getSSiteURL()); L~IE,4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H#+\nT2m
httpConnection.setRequestProperty("User-Agent","NetFox"); jk )Vb
q%>7L<r
@|BD|{k
int responseCode=httpConnection.getResponseCode(); GMz8B-vk
if(responseCode>=400) eI^gV'UK
{ 0mTEim
processErrorCode(responseCode); jO=*:{#x
return -2; //-2 represent access is error wtSvJI~o)
} Dv@PAnk3C
s2^B(wP
k=?^){[We
String sHeader; Jn=42Q:>
mwIk^Sz]@
8"x9#kyU<3
for(int i=1;;i++) (_K_`5d;QI
{ )Ob]T{GY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); X'f)7RbT
//Utility.log(in.readLine()); \b$<J.3
sHeader=httpConnection.getHeaderFieldKey(i); \ZMP_UU(
if(sHeader!=null) Z ] '>
{ r?pZ72q
if(sHeader.equals("Content-Length")) s O=4IBE
{ HMV)U{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4@6<
break; W .U+.hR
} T^]7R4Fg
} l xe`u}[
else 3htq[Ren
break; m2(E>raV6
} T6uMFD4 |
} !{(ls<
catch(IOException e){e.printStackTrace ();} pA.._8(t
catch(Exception e){e.printStackTrace ();} qp>N^)>
4d`+CD C
7Lg7ei2mN7
Utility.log(nFileLength); }Gr&w-v
n?:2.S.8
]v\^&7pW
return nFileLength; ;'}'5nO=$
} &cc9}V)M
mw4JQ\
)t%h[0{{
//保存下载信息（文件指针位置） RDJ+QOVKg
private void write_nPos() eLV.qLBUs
{ #dxvz^2V.3
try{ s]Gd-j
output = new DataOutputStream(new FileOutputStream(tmpFile)); .*Vkua
output.writeInt(nStartPos.length); j0x5@1`6G
for(int i=0;i<nStartPos.length;i++) ZVL gK}s
{ >aG=T{
// output.writeLong(nPos); WL U}
output.writeLong(fileSplitterFetch.nStartPos); PO o%^'(
output.writeLong(fileSplitterFetch.nEndPos); < bFy(+
} 2n)gpLIJ
output.close(); d)tiO2W
} Qdu$Os
catch(IOException e){e.printStackTrace ();} |9IC/C!HC
catch(Exception e){e.printStackTrace ();} 1k[GuG%/K
} 6{=_718l`
mj2Pk,,SA
jO8X:j09A
//读取保存的下载信息（文件指针位置） 8KMvAc
private void read_nPos() Uw)=WImz[
{ CxDcY
try{ 6+3$:?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jj,r <T
int nCount = input.readInt(); l5k?De_(x
nStartPos = new long[nCount]; {<K=*rrZ
nEndPos = new long[nCount]; 9x?'}
for(int i=0;i<nStartPos.length;i++) #{*LvI&
{ =7 w>wW-
nStartPos = input.readLong(); ZzcPiTSO
nEndPos = input.readLong(); V_"f|[1
} !D:Jbt@R<n
input.close(); dZ]Rqr _!
} %dW%o{
catch(IOException e){e.printStackTrace ();} ,mKObMu
catch(Exception e){e.printStackTrace ();} "3}<8c
} B!;+_%P76
-V5w]F'
/t5p-
private void processErrorCode(int nErrorCode) ]Blf9h7
{ 4h8*mMghs
System.err.println("Error Code : " + nErrorCode); bL`eiol6
} 2*2:-ocl$
z%sy$^v@vD
%e?fH.)
//停止文件下载 M0w/wt|
public void siteStop() }mk>!B}=
{ y=Q!-~5|fF
bStop = true; O/b+CSS1
for(int i=0;i<nStartPos.length;i++) C:i|-te
fileSplitterFetch.splitterStop(); @iLIU}+
"=A>}q@;H
rs]I
} Lm6**v
} u =J&~
//负责部分文件的抓取 h@1!T
**FileSplitterFetch.java ss iokLE
*/ 6BAW
package NetFox; pC(sS0J
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~OypE4./1
import java.io.*; >jTp6tu,
import java.net.*; *Y6xvib9*
I7(?;MpI
nidr\oFUIn
public class FileSplitterFetch extends Thread { 0*F}o)n/m
8P2 J2IU
)Gk`[*q ;
String sURL; //File URL O!&,5Dy
long nStartPos; //File Snippet Start Position F9flSeN
long nEndPos; //File Snippet End Position wtH~-xSB|
int nThreadID; //Thread's ID fU+Pn@'
boolean bDownOver = false; //Downing is over uQ/h'v
boolean bStop = false; //Stop identical l]6%lud8_
FileAccessI fileAccessI = null; //File Access interface Q(Gl{#b
nwmW.(R4
1m@^E:w
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9 OT,TpA
{ N#ioJ^}n:
this.sURL = sURL; eQDX:b
this.nStartPos = nStart; 3EK9,:<Cf
this.nEndPos = nEnd; L,LNv
nThreadID = id; M;.ZM<Ga
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )rtomp:X
} o:p *_>&
1G^#q,%X_v
GJA`l8`SQ
public void run() ae+*=,
{ yj_4gxJ\
while(nStartPos < nEndPos && !bStop) o{WyQ&2N
{ n<7q`tM#
ej(ikj~j
<AoXEuD
try{ >m6&bfy\q
URL url = new URL(sURL); 'T8W!&$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Mps5Vv
httpConnection.setRequestProperty("User-Agent","NetFox"); =^;P#kX
String sProperty = "bytes="+nStartPos+"-"; 5h{`<W
httpConnection.setRequestProperty("RANGE",sProperty); +-$Ko fnM
Utility.log(sProperty); 7h9U{4r: M
19UN*g3(
u bW]-U=T
InputStream input = httpConnection.getInputStream(); xTz%nx
//logResponseHead(httpConnection); W!L+(!&H
g(4bBa9y
n/4i|-^
byte[] b = new byte[1024]; r 2:2,5_
int nRead; /)3Lnn{W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) aSutM
{ 0<p{BL8
nStartPos += fileAccessI.write(b,0,nRead); S<wj*"|.s
//if(nThreadID == 1) PoSpkJH
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a;AzY'R
} >QkP7Kb
8V/L:h#7
~+6Vdxm
Utility.log("Thread " + nThreadID + " is over!"); L=; -x9
bDownOver = true; ??&<k
//nPos = fileAccessI.write (b,0,nRead); vX|UgK?2^
} *m+BuGt|
catch(Exception e){e.printStackTrace ();} }T_Te?<&
} p9eRZVy/
} ca<"
G&f8n
4Y\wnwI
//打印回应的头信息 <n"C,
public void logResponseHead(HttpURLConnection con) Nf41ZT~
{ ""iaGH+Cxw
for(int i=1;;i++) 5\fCd|
{ zg)sd1@
String header=con.getHeaderFieldKey(i); x2Lq=zwJ
if(header!=null) &HZmQ>!R D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RO(TvZ0pE
Utility.log(header+" : "+con.getHeaderField(header)); D<$XyP
else /iaf ^ >
break; l@Z6do
} ay )/q5
} #U mF-c
}iB|sl2J
t+uE
public void splitterStop() (qMj-l
{ ,M5}4E7L%s
bStop = true; r=.A'"Kf
} !^c@shLN4
dEa<g99[?
2BXy<BM @
} ~nLN`Hd
q!~ -(&S
xGk6n4Gg
/* V N{NA+I
**FileAccess.java 1 T<+d5[C
*//文件访问(定位，写) "_UdBG
package NetFox; aW_oD[l
import java.io.*; _*M42<wcO
9p* gU[
E>LkJSy=
public class FileAccessI implements Serializable{ Y*oDO$6
K6JVg$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CG\tQbum
RandomAccessFile oSavedFile; "ICC B1N|
long nPos; -7H^n#]
h"mi"H^o
BimjQ;jtI
public FileAccessI() throws IOException eDI=nSo
{ e!-,PU9+
this("",0); W<ZK,kv
} O)|P,?
u|#>32kV
#hfuH=&oh
public FileAccessI(String sName,long nPos) throws IOException 2zSG&",2D
{ ] Wy)
oSavedFile = new RandomAccessFile(sName,"rw"); Psura$:
this.nPos = nPos; u9woEe?
oSavedFile.seek(nPos); Jq.lT(E8D
} O=cxNy-I
,fDEz9-,
`^JJ&)4iv
public synchronized int write(byte[] b,int nStart,int nLen) n"PJ,ao
{ EI>6Nh
int n = -1; %=we`&
try{ Z7rJ}VP
oSavedFile.write(b,nStart,nLen); Cb t{H}I3
n = nLen; ]M>9ULQ
} N]EcEM#
catch(IOException e) d6{Gt"
{ f*{ YFg?*&
e.printStackTrace (); sxKf&p;
} ?^mi3VM
-~[9U,
/^{BUo
return n; Jf)bHjC_V
} JCcZuwu[
9fnA
#o/H~Iv
} 5Z/GK2[HL
hRI"y":zD
>7`<!YJkK
/* 'TC/vnM
**SiteInfoBean.java .MW@;
*/ &;,,H< p
package NetFox; 1(Y7mM8\
93qwH%
`!:q;i]}
public class SiteInfoBean { 1% F?B-k
<$w?/y/'
7'-Lp@an
private String sSiteURL; //Site's URL 9j]sD/L5q
private String sFilePath; //Saved File's Path HmfG$Z
private String sFileName; //Saved File's Name X:a`B(@S
private int nSplitter; //Count of Splited Downloading File a {}|Bf<
<}U'V}g
L9Z;:``p
public SiteInfoBean() _Y=2/*y^
{//nSplitter的缺省值为5 <^~FLjsfg
//default value of nSplitter is 5 .?p\n7
this("","","",5); /&& 2u7*
} do-ahl,
etT +
H.<a`mm8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \;-fi.Hrf$
{ |6UtW{2I/
sSiteURL= sURL; [ xOzzp4
sFilePath = sPath; ;=j@, yu
sFileName = sName; k:2QuG^
this.nSplitter = nSpiltter; )#a[-.OI
<^b7cOFQ
G2LK]
} <H1`
(Rk_-9_E.
scuHmY0
public String getSSiteURL() ,P'P^0qJ
{ Y={&5Mir
return sSiteURL; RjF'x
} QIN."&qC^
v5;I]?72l~
9Suu-A
public void setSSiteURL(String value) d_n7k g+
{ ;N B:e
sSiteURL = value; -[= drj9I
} svelYe#9z
g~7Ri-"
FJ*i\Q/D
public String getSFilePath() Ftw;Yz
{ l$K,#P<)
return sFilePath; AM"Nn L"
} )&era` e[
Uie?9&3
O20M[_S
public void setSFilePath(String value) e{;OSk`x
{ |9"p|6G?B
sFilePath = value; 7&`}~$>}>e
} a9n^WOJ6
qQpnLV4
(>mI'!4d
public String getSFileName() YY?a>j."a
{ /&u<TJ4
return sFileName; N=:5eAza
} 0JgL2ayIVI
`28};B>
%}86D[PF
public void setSFileName(String value) M :3u@06a
{ B!gGK|8
sFileName = value; $F.([?)k?
} ELh8ltLY
Xi?b]Z
pE{yv1Yg
public int getNSplitter() )$w*V9d
{ "#v=IJy&r
return nSplitter; vHAg-Avc
} \BWykA>
j1SMeDDM ~
k5kdCC0FCk
public void setNSplitter(int nCount) )uv=S;+
{ _3]][a,
nSplitter = nCount; {_(\`>
} DC1'Kyk
} =0@&GOq
kOvDl!^
tvXW
/* 6"c1;P!4
**Utility.java 'Dvv?>=&
*/ mh<=[J,%p
package NetFox; :Rs^0F8)c
"MIq.@8ra
c}3W:}lW
public class Utility { t}v2$<!I
b{fQ|QD{^E
@fuM)B1"
public Utility() X7,PEA
{ Q'k\8'x
"x@='>:$
p8s:g~ W
} |uW:r17
L< zD<M
//线程睡眠 +A~\tK{
public static void sleep(int nSecond) tO_H!kP
{ +(uYwdcN
try{ F}"]92
Thread.sleep(nSecond); LqdY Qd51
} LZ@|9!KDw
catch(Exception e) &z"krM]G
{ jCTAKaq
e.printStackTrace (); }F+zs*S
} Qu,8t8
} d:G]1k;z
P}.7Mehf
//日志 AxxJk"v'y
public static void log(String sMsg) m/NdJMoN=
{ 3] 1-M
System.err.println(sMsg); OB~X/
} "O8gJ0e
IVlf=k
) 'j:
public static void log(int sMsg) +UJuB
{ _C\[DR0n
System.err.println(sMsg); 1FtM>&%4
} uxg9yp@|
} v(OBXa9
\c[IbL07
{cpEaOyOM
/* aA-
**TestMethod.java PSawMPw
*/ tNVV)C
package NetFox; %gnM(pxl
[i0Hm)Bd3
k%y9aO
public class TestMethod { T0)"1D<l
_LwOOZj
`nUO l
public TestMethod() l"n{.aL
{ ///xx/weblogic60b2_win.exe >;z<j$;F<
try{ iCP/P%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CE15pNss
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +i\&6HGK;-
SiteFileFetch fileFetch = new SiteFileFetch(bean); Sx
fileFetch.start(); #d{=\$=
} Kb =@ =Xta
catch(Exception e){e.printStackTrace ();} Z ,^9Z
^IKO2Ft
]nhr+;of/-
} b;|55Y
KYJjwXT28W
~)?
public static void main(String[] args) lyCW=nc
{ y/V%&.$o=
new TestMethod(); GRy-+#,b"
} *&AfR8x_z
} {{C`mgC
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