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)); l0%qj(4`6&
} N-g=_86C"
for(int i=0;i<nEndPos.length-1;i++) [LHx9(,NM
{ A^9RGz4=
nEndPos = nStartPos[i+1]; %1Pn;bUU!
} !L)~*!+Gf
nEndPos[nEndPos.length-1] = nFileLength; as%ab[ fX
} ?9)-?tZ^Q
} wh~g{(Xvq
(g8<"< N?
=ZaTD-%id
//启动子线程 ee0)%hc1t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vg6'^5S7
for(int i=0;i<nStartPos.length;i++) 3TDjWW;#~
{ @TTB$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D0f.XWd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NWt`X!
nStartPos,nEndPos,i); (6*CORE
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~)kOOoH
fileSplitterFetch.start(); r- :u*
} 8LMO2Wyq
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uIO<6p)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }{(dG7G+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !&k}YF
nEndPos = " + nFileLength); GQP2-cSZ
// fileSplitterFetch[nPos.length-1].start(); XYM 5'
YgN:$+g5
x=%p~$C
//等待子线程结束 e/p2| 4;
//int count = 0; 0F495'*A
//是否结束while循环 _+vE(:T
boolean breakWhile = false; >5aZ?#TS1
A=z+@b6
TfbB1
while(!bStop) ("7rjQjRz
{ P&s-U6
write_nPos(); >4.K>U?0FC
Utility.sleep(500); el;eyGa
breakWhile = true; 0"vI6Lm
%}nNwuJ
#9a\Ab
for(int i=0;i<nStartPos.length;i++) 7t@r}rC,K
{ v|&Nh?r
if(!fileSplitterFetch.bDownOver) a->;K+
{ @Weim7r
breakWhile = false; 0^L>J"o
break; 007(k"=oV
} TBGN',,
} _=wu>h&7
if(breakWhile) [vJLj>@
break; I)B+h8l72<
K>tubLYh
l=*60Ag\J~
//count++; a%"27 n(M
//if(count>4) Hj>(kL9H
// siteStop(); W@vt6v
} QQnpy.`:/
<;R}dlBASW
]f3eiHg*
System.err.println("文件下载结束！"); ;9+[t8Y)D
} lD%Fk3
catch(Exception e){e.printStackTrace ();} M_+"RKp
} w Bi'KS
i1OF@~?
E=-ed9({:
//获得文件长度 cQ?eL,z
public long getFileSize() 7j ]d{lD
{ $mV1K)ege
int nFileLength = -1; 907N;r
try{ VDyQv^=#
URL url = new URL(siteInfoBean.getSSiteURL()); vSOO[.=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NM`5hd{
httpConnection.setRequestProperty("User-Agent","NetFox"); :oYz=c
h2b,(
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int responseCode=httpConnection.getResponseCode(); rY~!hZ
if(responseCode>=400) ,#u"$Hz8p
{ sUCI+)cM3
processErrorCode(responseCode); >;$C@
return -2; //-2 represent access is error )tq&l>0h
} _XO3ml\x@
ZCT\4Llv#
G`_LD+
String sHeader; Qcy /)4Hfg
t==CdCl
Xiy9Oeq2uh
for(int i=1;;i++) <?Z[X{
{ ``zgw\f[%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;V=Y#|o
//Utility.log(in.readLine()); bc?\lD$$
sHeader=httpConnection.getHeaderFieldKey(i); b6mSPH@
if(sHeader!=null) >o]!-46
{ R 2{kS
if(sHeader.equals("Content-Length")) 95wi~^^
{ ji|+E`Nii
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _6tir'z
break; VP7g::Ab
} WS!:w'rzr
} wNk 0F7Ck
else ,EE,W0/zzM
break; K~C6dy
} EO_:C9=d{
} -KuC31s_W
catch(IOException e){e.printStackTrace ();} B"@3Qav3
catch(Exception e){e.printStackTrace ();} ,esryFRG
K4G43P5q`
kE8\\}B7
Utility.log(nFileLength); isG8S(}IW&
Q1b<=,
.+@;gVZx1
return nFileLength; XtJIaD|:3
} FyF./
yobcAV`
UgVLHwkvk
//保存下载信息（文件指针位置） @26gP:Um
private void write_nPos() TZl^M h[a
{ )U?5O$M;lE
try{ -E$(<Pow~\
output = new DataOutputStream(new FileOutputStream(tmpFile)); tyW5k(>
output.writeInt(nStartPos.length); R2e":`0I
for(int i=0;i<nStartPos.length;i++) *NC9S,eSP
{ ]FQO@y
// output.writeLong(nPos); ]g3RVA%\l
output.writeLong(fileSplitterFetch.nStartPos); 5 $vUdDTg
output.writeLong(fileSplitterFetch.nEndPos); 6SJryf~w
} @(m+B\
output.close(); @X|Mguq5
} u!B6';XY
catch(IOException e){e.printStackTrace ();} b%-S'@ew
catch(Exception e){e.printStackTrace ();} y[C++Q
} 4kNiS^h
I:L}7uA[t
ma gZmY~
//读取保存的下载信息（文件指针位置） [f1'Qb
private void read_nPos() Fv<^\q
{ Fx3CY W
try{ e#5LBSP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 'o!{YLJ fM
int nCount = input.readInt(); _x2i=SFo*$
nStartPos = new long[nCount]; ,Vc>'4E-
nEndPos = new long[nCount]; I<``d Ne9Q
for(int i=0;i<nStartPos.length;i++) 9tMaOm
{ ^%qe&Pe2
nStartPos = input.readLong(); :pp@x*uNP
nEndPos = input.readLong(); Fuz'!
} +n)_\@aQ
input.close(); !jySID?q
} ZNKopA(=|%
catch(IOException e){e.printStackTrace ();} r*r3QsO
catch(Exception e){e.printStackTrace ();} js$L<^7
} _,ki/7{
s-Z<
>,9ah"K_x
private void processErrorCode(int nErrorCode) wDvG5
{ pz hPEp;
System.err.println("Error Code : " + nErrorCode); kA"|PtrW
} j@Ta\a-,x
VqIzDs
}x9D;%)/
//停止文件下载 ^5GyW`a}
public void siteStop() )Z=S'm k4_
{ XHh!Q0v;
bStop = true; 1^HmM"DD
for(int i=0;i<nStartPos.length;i++) u alpm#GU
fileSplitterFetch.splitterStop(); 4#D<#!]^
,(@JNtx
t/kMV6
} w<P$)~6
} wAvnj
//负责部分文件的抓取 *6`};ASK
**FileSplitterFetch.java BKV,V/*p
*/ P&=H<^yd
package NetFox; # h/#h\
%aB RL6
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import java.io.*; .,9e~6}
import java.net.*; n|M~C\*
{tDH !sX
\Qgc7ev
public class FileSplitterFetch extends Thread { y"L7.B
og~Uv"&?T
Po1/_#mu
String sURL; //File URL 0XWhSrHM
long nStartPos; //File Snippet Start Position XzD+#+By
long nEndPos; //File Snippet End Position Q`BK R]/
int nThreadID; //Thread's ID mWP1mc:M(
boolean bDownOver = false; //Downing is over uE]Z,`e
boolean bStop = false; //Stop identical *q$O6B-
FileAccessI fileAccessI = null; //File Access interface AhCqQ.O71
>* )fmfY
^aONuG9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }ZKG-~
{ .*k$abb
this.sURL = sURL; ~x-v%x6
this.nStartPos = nStart; I"hlLP
this.nEndPos = nEnd; yW)&jZb"(
nThreadID = id; 99YgQ Y]HO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {2v,J]v_[
} SmUj8?6"
+I>V9%%vW_
$[xS>iuD
public void run() r1A<XP|1?I
{ 49Q tfk
while(nStartPos < nEndPos && !bStop) q(9S4F
{ +td]g9Ie
51Q m2,P1^
Q|7$SS6$
try{ ?lPyapA]
URL url = new URL(sURL); 8JFvz(SK>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4/?@%
httpConnection.setRequestProperty("User-Agent","NetFox"); ecsQshR
String sProperty = "bytes="+nStartPos+"-"; Re<@.d
httpConnection.setRequestProperty("RANGE",sProperty); |6O7_U#q
Utility.log(sProperty); NE)Yd7m-
5I6u 2k3
|\<L7|hb9
InputStream input = httpConnection.getInputStream(); Errs6
//logResponseHead(httpConnection); crbph.0
]/6i#fTw
X? l5}
byte[] b = new byte[1024]; /_D_W,#P
int nRead; 3Ow bU
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t8ZzBD!dP
{ f6])M)
nStartPos += fileAccessI.write(b,0,nRead); 8svN*`[
//if(nThreadID == 1) oB$c-!&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L:_GpZ_
} mFgrT
Z'!i"Jzq|{
?_t_rF(?6
Utility.log("Thread " + nThreadID + " is over!"); rT"3^,,
bDownOver = true; kQw%Wpuq[/
//nPos = fileAccessI.write (b,0,nRead); V~ q b2$
} [aF"5G
catch(Exception e){e.printStackTrace ();} %5ovW<E:
} WS6;ad;|
} BS|$-i5L
d^+0=_[PmK
Mpx98xcO
//打印回应的头信息 Kn*LwWne
public void logResponseHead(HttpURLConnection con) 5kik+
{ &Sdf0"
for(int i=1;;i++) 3%(,f,
{ ]R*h3U@5#K
String header=con.getHeaderFieldKey(i); Y.b?.)u&
if(header!=null) jYk5]2#A
//responseHeaders.put(header,httpConnection.getHeaderField(header)); WYm<_1
Utility.log(header+" : "+con.getHeaderField(header)); {l9gYA
else fl}!V4
break; ZKTY1JW_
} 8.zYa(<2
} }Y!v"DO#Q*
\k9]c3V
<%N*IE"q
public void splitterStop() .x'?&7#(
{ h7kn >q;
bStop = true; Vj[hT~{f
} 'mTQ=1
_-|+k
&d_2WQ}
} e81+as
L_Xbca=
nIWY<Z"
/* &>xz
**FileAccess.java D!V~g72j
*//文件访问(定位，写) `4-N@h
package NetFox; RpwDOG
import java.io.*; eX$RD9 H
kD me>E=
()W`4p
public class FileAccessI implements Serializable{ j;J`PH
6F_:,b^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Zd}12HFq
RandomAccessFile oSavedFile; g=$nNQ \6=
long nPos; O$7cN\Z
>zfFvx_q
*Ksk1T+>
public FileAccessI() throws IOException '<U4D
{ pv,z$3Q
this("",0); *RmD%[f
} K SJ Ko
YQ>O6:%
H6hhU'Kxf8
public FileAccessI(String sName,long nPos) throws IOException 9\VV++}s>o
{ >mj WC) U
oSavedFile = new RandomAccessFile(sName,"rw"); d*dPi^JjC
this.nPos = nPos; 7l4}b^>/`
oSavedFile.seek(nPos); n)PqA*
} q)3QmA~
T>|Y_3YO_a
D67z6jep(
public synchronized int write(byte[] b,int nStart,int nLen) Md&K#)9,(
{ Dxe]LES\]
int n = -1; |$Cfm}
try{ 1}~ZsrF
oSavedFile.write(b,nStart,nLen); oDWNOw
n = nLen; 3X#Cep20a
} >FS}{O2c
catch(IOException e) Rh%A^j@
{ L]q%;u]8!
e.printStackTrace (); P8[k1"c!
} \A6}=
?e\u_3-9
PPde!}T$
return n; p]qz+Z/
} !ScEA=
/!sGO:
OBf$Z"i
} X/Ii}X/p
qIxe)+.
.O SQ8W}
/* IP^1ca#<
**SiteInfoBean.java 5cb8=W-
*/ b3ys"Vyn
package NetFox; Z>~7|vl
:1;"{=Yx}
6]mAtA`Y
public class SiteInfoBean { Z= =c3~
yZ)-=H
p^w_-(p
private String sSiteURL; //Site's URL H`,t"I
private String sFilePath; //Saved File's Path b#*"eZj
private String sFileName; //Saved File's Name ==S^IBG
private int nSplitter; //Count of Splited Downloading File `)>}b 3
2t?Vl%<
=7EkN% V:{
public SiteInfoBean() _p?s[r*
{//nSplitter的缺省值为5 ,BR W=
//default value of nSplitter is 5 4]ko
this("","","",5); 89{`GKWX
} zYM0?O8pJ~
e-nwR
$RYOj{1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R[rOzoNp0
{ FH{p1_kZ=
sSiteURL= sURL; {{AZW
sFilePath = sPath; hxt;sQAo{
sFileName = sName; q3`~uTzk
this.nSplitter = nSpiltter; q.j$]?PQ
C=bQ2t=Z
U;M!jj
} Gz4LjMQ &
7eW6$$ju,N
iba8G]2
public String getSSiteURL() z/nW;ow
{ gGx<k3W^
return sSiteURL; ND/oKM+?
} :(4q\~
S4rm K&
0Hx'C^m72
public void setSSiteURL(String value) _:FD#5BZ1
{ )P,pW?h$
sSiteURL = value; cM\BEhh
} mex@~VK
P.jy7:dB,
t>x!CNb'C
public String getSFilePath() WO6+r?0M2
{ b;nqhO[f}
return sFilePath; P76gJ@#m
} <sX_hIA^Fx
yZ]?-7
deJ/3\t
public void setSFilePath(String value) I:0dz:T7*
{ a-AA$U9hj
sFilePath = value; *$3p3-
} $M~`)UeV_
F"QJ)F
c=^69>w
public String getSFileName() BU7QK_zT:
{ h)aLq
return sFileName; k=G c#SD5_
} Cq3Au%7
f0YBy<a
7K+eI!m.s
public void setSFileName(String value) m>?|*a,
{ N`qGwNT%G
sFileName = value; 16Jjf|]j
} FC
gZ-:4G|J
0.c96&
public int getNSplitter() Sy<io@df
{ rbs&A{i
return nSplitter; uo*lW2&U
} Q.\vN-(
?A~=.u@[d
kWs:7jiiu
public void setNSplitter(int nCount) iRqLLMrn
{ cVYu(ssC4
nSplitter = nCount; $"k1^&&E
} %NfH`%`
} s@Loax6@B
/iJsa&W}
2sVDv@2
/* ?}S!8;d
**Utility.java 6WoFf
*/ wUfPnAD.'
package NetFox; E^m)&.+'M
/<dl"PWkJv
C;#gy-
public class Utility { P7REE_<1
}=.C~f]A
ca,c+5
public Utility() c{39,oF
{ ]7RK/Zu i
nA%8 bZ+
XpA|<s
} &)|f|\yh"
lwo,D}
//线程睡眠 uKB V`I
public static void sleep(int nSecond) :qV|rih_Q
{ >SS^qjh/
try{ A0Q1"b=
Thread.sleep(nSecond); J7~Kjl
} =$ubSfx
catch(Exception e) tf1Y5P$
{ Mko,((>I1
e.printStackTrace (); }uO2x@
} 4{b/Nv:b
} v+dT7*^@
ha9 dz
//日志 (C%qA<6
public static void log(String sMsg) t+jdV
{ 3M'Y'Szm
System.err.println(sMsg); ej&o,gX
} .Np!Qp1*
4 XGEw9`3
jO`L:D/C
public static void log(int sMsg) vkW;qt}yO
{ 'C;KNc
System.err.println(sMsg); r4iT 9D
} &yqk96z
} z^y -A?
GkKoc v
FY]Et=p
/* ~dLe9-_9
**TestMethod.java ?3i<^@?
*/ cCIs~*D
package NetFox; $cLZ,N24
zP/SDW
APU~y5vG (
public class TestMethod { $]?M[sL\N7
W=2]!%3#
;)sC{ "Jb
public TestMethod() 5 L-6@@/
{ ///xx/weblogic60b2_win.exe zCu+Oi6
try{ nQn=zbZ3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9A}y^=!`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )Rj?\ZUR
SiteFileFetch fileFetch = new SiteFileFetch(bean); cO-^#di
fileFetch.start(); 0_t9;;y :
} 5o0H7k]
catch(Exception e){e.printStackTrace ();} SW HiiF@
:;Npk9P(N
nrM-\'
} 'ztY>KVj
|1T[P)Q
`|:` yl
public static void main(String[] args) uFOYyrESc
{ ={{q_G\WD
new TestMethod(); e C&!yY2g
} K=dG-+B~}
} Cn>t"#zs!~
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