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)); aANzL
} !&f>,?wlP
for(int i=0;i<nEndPos.length-1;i++) (2l?~CaK
{ @hG]Gs[,o
nEndPos = nStartPos[i+1]; TwT@_~IM
} jgyXb5GY
nEndPos[nEndPos.length-1] = nFileLength; 6+iZJgwAy
} gz~)v\5D/
} &~ .n}h&
&$x1^
&x#3N=c#
//启动子线程 iiWm>yy
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yQ/E0>Uj!
for(int i=0;i<nStartPos.length;i++) Q2 S!}A
{ ?kBX:(g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B=;pwX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5ieF8F%
nStartPos,nEndPos,i); OngUZMgdb
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^rX5C2}G\D
fileSplitterFetch.start(); Yo^9Y@WDW
} fhp+Ep!0Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VmbfwHRWb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R/|2s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +p\+15
nEndPos = " + nFileLength); DQ{"6-
// fileSplitterFetch[nPos.length-1].start(); @krh<T6|
U'Mxf'q
=*\(Y(0
//等待子线程结束 xfFsW^w
//int count = 0; "~nUwW|=1
//是否结束while循环 Vgg'5o&.
boolean breakWhile = false; SU$%nK)
: 6|nXL
j +u3VP
while(!bStop) Frd`u.I
{ f8vWN
write_nPos(); c_Fz?R+f?K
Utility.sleep(500); 'X(Sn3
breakWhile = true; }P(<]UF
0/~20KD{s
a*3h|b<
for(int i=0;i<nStartPos.length;i++) DFvj
{ D:DtP6
if(!fileSplitterFetch.bDownOver) FC&841F
{ ` &{
breakWhile = false; /8Xd2-
break; s<b(@L 1
} 9_&N0>OF
} 0\tdxi
if(breakWhile) TMAart;<
break; 3zsjL=ta
in>.Tax*
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//count++; V=-hqo(
//if(count>4) .cCB,re
// siteStop(); +h?Rb3=S
} 8;+dlWp
G$7!/O%#_
Zf*DC~E_
System.err.println("文件下载结束！"); f)9{D[InM^
} d:GAa
catch(Exception e){e.printStackTrace ();} m1{OaHxKh
} y-R:-K XH=
JXKo zy41
me`|i-
//获得文件长度 %}ASll0uq
public long getFileSize() NxzRVsNF
{ ,Z aPY
int nFileLength = -1; Fb^f`UI
try{ VcpN PU6
URL url = new URL(siteInfoBean.getSSiteURL()); LP:U6 Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ew$-,KC[
httpConnection.setRequestProperty("User-Agent","NetFox"); OtD!@GQ6
F0 ^kUyF|
cjyb:gAO
int responseCode=httpConnection.getResponseCode(); $?Z-BD1
if(responseCode>=400) > a"4aYj
{ VU ,tCTXz
processErrorCode(responseCode); <cNg_ZZ;8
return -2; //-2 represent access is error gVU&Yl~/^
} rG"QK!R5
iD`>Bt7gD
#1VejeTi
String sHeader; jB-wJNP/
oaMh5FPy
kXY p.IVA
for(int i=1;;i++) l>{+X )
{ (rB?@:zN
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g'nN#O
//Utility.log(in.readLine()); wfY]J0l
sHeader=httpConnection.getHeaderFieldKey(i); y_A7CG"^
if(sHeader!=null) NI)q<@ju
{ a,~}G'U
if(sHeader.equals("Content-Length")) rwCjNky!
{ kO'_g1f<[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $]I",ef
break; e(~Y!:Q#O
} \h UE,^
} YdiXj |k+
else q+)csgN
break; UukHz}(E
} !PuW6
} \r^*4P,,
catch(IOException e){e.printStackTrace ();} "u.4@^+i
catch(Exception e){e.printStackTrace ();} q A?j-H
01AzM)U3"m
Qe;j_ BH
Utility.log(nFileLength); ptvM>zw'~g
Tj_~BT
rn"}@5
return nFileLength; +~cW0z
} r5(-c]E7
[2Rw)!N
W y%'<f
//保存下载信息（文件指针位置） 1 6G/'Hb
private void write_nPos() I15g G.)
{ L; f
try{ ]id5jVY
output = new DataOutputStream(new FileOutputStream(tmpFile)); GFmVR2z_+
output.writeInt(nStartPos.length); 8"2X 8C8
for(int i=0;i<nStartPos.length;i++) elw}(l<F
{ eq(Xzh
// output.writeLong(nPos); =h/0k y
output.writeLong(fileSplitterFetch.nStartPos); u>I;Cir4
output.writeLong(fileSplitterFetch.nEndPos); @o6^"
} 53jtwklA
output.close(); L.1pO2zPe
} Bp:i[9w
catch(IOException e){e.printStackTrace ();} a eo/4
catch(Exception e){e.printStackTrace ();} BR[f{)a5
} b*@y/ e\u`
0"O22<K3a
A"`(^#a
//读取保存的下载信息（文件指针位置） .f~x*@
private void read_nPos() q9mYhT/Im
{ p/GYfa dU
try{ AroXf#.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1XvB,DhJ
int nCount = input.readInt(); ]&kzIxh
nStartPos = new long[nCount]; jf'#2-
nEndPos = new long[nCount]; BoMf#l.3B
for(int i=0;i<nStartPos.length;i++) KXy|Si8w
{ U3zwC5}BN
nStartPos = input.readLong(); a|\ZC\(xI
nEndPos = input.readLong(); p"XQJUuD
} .Lc<1s
input.close(); i'}Z>g5D
} (HZzA7eph
catch(IOException e){e.printStackTrace ();} !`-/E']/
catch(Exception e){e.printStackTrace ();} F6xQ`T|
} m+Bt9|d
beM}({:`
u teI[Q
private void processErrorCode(int nErrorCode) XCTee
{ I!;&#LT+b
System.err.println("Error Code : " + nErrorCode); hiN6]jL|O
} RO1xcCp
9G'Q3? z
5$ra4+k0
//停止文件下载 e2?7>?
public void siteStop() !SFF 79$c
{ <Hq|<^_K
bStop = true; X(;,-7Jw
for(int i=0;i<nStartPos.length;i++) T;u>]"S
fileSplitterFetch.splitterStop(); BEv>?T 0
8yDu(.Q
1Lf:TQB
} C$1}c[
} k^IC"pUc
//负责部分文件的抓取 Jm+hDZrW
**FileSplitterFetch.java ,&\uuD&.@
*/ 6jRUkI-!
package NetFox; 1x^(vn#=
-$]Tn#`Fb
k8;
import java.io.*; D%0GXUp
import java.net.*; W&U Nk,
\HzI*|*A
fi2@`37PM
public class FileSplitterFetch extends Thread { <R.5Ma
N:y3tpG
6BJPQdqSl
String sURL; //File URL LI&+5`
long nStartPos; //File Snippet Start Position o!3-=<^
long nEndPos; //File Snippet End Position ZMHb
int nThreadID; //Thread's ID :(|;J<R%_
boolean bDownOver = false; //Downing is over Ba\l`$%X
boolean bStop = false; //Stop identical JRm:hf'
FileAccessI fileAccessI = null; //File Access interface s9wcZO
P>dMET
hoc$aqP6pp
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pOCLyM9c
{ ueiXY|
this.sURL = sURL; )k.[Ve
this.nStartPos = nStart; 'wd-!aZAd
this.nEndPos = nEnd; ~7W?W<
nThreadID = id; IQS:tL/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 N%A[}Y0;MW
} \V|\u=@H
:/BU-SFK^
L//Z\xr|
public void run() Wh:SZa|
{ u(7PtmV[!
while(nStartPos < nEndPos && !bStop) 5_@8g+~
{ McgTTM;E
%r0yBK2uOp
3+<}Hm+
try{ !po8[fz~x
URL url = new URL(sURL); HXTBxh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8"4&IX
httpConnection.setRequestProperty("User-Agent","NetFox"); ey@]B5
String sProperty = "bytes="+nStartPos+"-"; 3%]%c6
httpConnection.setRequestProperty("RANGE",sProperty); 9=j"kXFf
Utility.log(sProperty); 2NLD7A
a{7>7%[
sS,Swgr
InputStream input = httpConnection.getInputStream(); [<Wo7G1s
//logResponseHead(httpConnection); lCDu,r;\
2Y)3Ue
*7Ct#GC
byte[] b = new byte[1024]; +s:!\(BM
int nRead; -v4kW0G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a W`q
{ ngprTMO$&
nStartPos += fileAccessI.write(b,0,nRead); ,%#FK|
//if(nThreadID == 1) Ji_3*(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Bf$YwoZov
} O+Fu zCWj
gRS}Y8
){|Bh3XV
Utility.log("Thread " + nThreadID + " is over!"); *.0}3
bDownOver = true; 1MH[-=[Q
//nPos = fileAccessI.write (b,0,nRead); {H+~4XG
} >;eWgQ6V
catch(Exception e){e.printStackTrace ();} aU,Zjm7fp
} (c ?OcwTH
} (PjC]`FK
XYtDovbv&
N<1u,[+
//打印回应的头信息 c rPEr
public void logResponseHead(HttpURLConnection con) gnW`|-:\
{ <=A1d\
for(int i=1;;i++) 0Zp) DM
{ t@[&8j2B>
String header=con.getHeaderFieldKey(i); P#(BdKjM
if(header!=null) ~ztsR;iL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =B g
Utility.log(header+" : "+con.getHeaderField(header)); a9C8Q l
else Ah,X?0+
break; GsG.9nd
} !rzbm&@
} 9kmkF,
>M{=qs
Bb2;zOGdA
public void splitterStop() XBE+O7
{ A*jU&3#
bStop = true; j:# wt70
} `9BZ))Pg
V9*Z
VMPBM:kG
} nFU'DZ
p< i;@H;:
@:\Iw"P
/* U|QLc
**FileAccess.java 4.:2!Q
*//文件访问(定位，写) &<}vs`W
package NetFox; F+mn d,3
import java.io.*; hI.@!$~=
kLa9'c0
T 22tZp
public class FileAccessI implements Serializable{ FES_:?.0
v#1}( hb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h+)XLs
RandomAccessFile oSavedFile; 'NyIy:
long nPos; (_h<<`@B
C7#ji"t
od=%8z
public FileAccessI() throws IOException [IT*>;b+?
{ u;f${Wn'3
this("",0); 22aS <@}
} 6-8,qk
qdkhfm2(K
Bw _^"e8X
public FileAccessI(String sName,long nPos) throws IOException \c1u$'|v
{ bBwQ1,c$
oSavedFile = new RandomAccessFile(sName,"rw"); iV#sMJN9
this.nPos = nPos; dU`kJ,=Z
oSavedFile.seek(nPos); Ws%@SK
} Y+vG]?D
q<.m@q
[B<htD&
public synchronized int write(byte[] b,int nStart,int nLen) 0c6b_%Rd
{ KE>|,Ur
int n = -1; v_M-:e3`
try{ 1iNq|~
oSavedFile.write(b,nStart,nLen); Vwxb6,}Z
n = nLen; P2la/jN
} {m%]`0
catch(IOException e) f793yCiG
{ zh8\ _>+
e.printStackTrace (); 9e5XS\
} je_:hDr
= BcKWC
[]^fb,5a
return n; jSi\/(E
} =.T50~+M
Nfv.v1Tt+
@">^2
} ?'>pfU
&CP]+ at
N_jpCCG~
/* +H"[WZ5
**SiteInfoBean.java jQ>~
*/ $K& #R-
package NetFox; '" MT$MrT
1ym^G0"s
'M20v-[
public class SiteInfoBean { {`RCh]W
py\KY R
]#$l"ss,
private String sSiteURL; //Site's URL m9~cQ!m
private String sFilePath; //Saved File's Path 6:\0=k5
private String sFileName; //Saved File's Name PB[Y^q
private int nSplitter; //Count of Splited Downloading File *vFXe_.
B\WIoz;'
\%],pZsA~
public SiteInfoBean() 3m;*gOLk6
{//nSplitter的缺省值为5 'xK ,|U
//default value of nSplitter is 5 {&u`d.Lk2p
this("","","",5); E^ub8
} 0c{-$K}
q>X30g
JWB3;,S
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) AFMIp^F
{ dd?ZQ:n
sSiteURL= sURL; _P].Z8
sFilePath = sPath; IA6,P>}N
sFileName = sName; qoZUX3{
this.nSplitter = nSpiltter; 6h5DvSO
5vP=Wf cW
d ,"L8
} G~.bi<(v
i>elK<R4
PxAUsY
public String getSSiteURL() 6gy;Xg
{ ta;q{3fe
return sSiteURL; GkU]>8E'"
} :o37 V!
+cXdF
1uwzo9Yg
public void setSSiteURL(String value) QV%,s!_b
{ 1r:i'cWh
sSiteURL = value; P<E!ix
} =|j~*6Hd
ta
b^s>yN
public String getSFilePath() tNbL)
{ 506AvD
return sFilePath; B5R/GV
} <>l!
,qUOPW?=
|g`:K0BI
public void setSFilePath(String value) AQ<2 "s
{ 'uBagd>*
sFilePath = value; W{!Slf
} gH u!~l
Au"7w=G`f
C@F3iwTtp
public String getSFileName() EJByYk
{ M[:},?ah0
return sFileName; [&MhAzF
} e$Npo<u
b0:5i<"w6
i w(4!,4~
public void setSFileName(String value) b^dBX
{ 9zKbzT]
sFileName = value; =5kTzH.
} IpYw<2'
g[D`.
#J w\pOn
public int getNSplitter() #Zq[.9!q{
{ \X]
return nSplitter; yv+DM`0
} o|njgmF;\
kN8?.V%Utw
x7!YA>
public void setNSplitter(int nCount) m&I5~kD
{ q% pjY
nSplitter = nCount; 0(h'ZV
} egHvI&w"o
} n[c/L8j
)BX-Y@fpA
uzO3_.4Y
/* ~=Q|EhF5
**Utility.java m2r%m y
*/ 41s[p56+@
package NetFox; *nYb9.T]i
Op 0Qpn
HLYo+;j3|
public class Utility { N1l&$#Fr!s
*{%d{x}l
*#&s+h,^
public Utility() wf&1,t3Bgn
{ <1XJa2
nep-?7x
2nv-/%]
} #Py\'
Ynx.$$`$=
//线程睡眠 \?K>~{)
public static void sleep(int nSecond) 5Vu@gRk_
{ a"pejW`m
try{ ffibS0aM
Thread.sleep(nSecond); `7o(CcF6H
} k_A 9gj1
catch(Exception e) 0o*
{ !vwx0
e.printStackTrace (); d_!lRQ^N
} 5;yVA
} Y:3\z?oV[
FZJyqqA$_
//日志 \-scGemH
public static void log(String sMsg) qE)G;Y<,1
{ <CM}g4Y
System.err.println(sMsg); 1Zi(5S)
} W:XN!
$/XR/
rxM)SC;P
public static void log(int sMsg) 99mo]1_
{ @uzzyp r>
System.err.println(sMsg); ;=oGg%@aP
} Z`97=:W
} $"`9QD~
h6Q-+_5
eK_Yt~dj
/* p}{V%!`_
**TestMethod.java !tr /$
*/ .0H!B#9
package NetFox; F)Qj<6
TU,k( `tn<
=S|^pN
public class TestMethod { Kj`sq":Je0
o7#Mr`6H
S&w(H'4N
public TestMethod() ].,TSnb
{ ///xx/weblogic60b2_win.exe /*2sg>e'QF
try{ cQ<* (KU
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); VN[i;4o:|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .jps6{
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3NA G}S
fileFetch.start(); ;rJ
} 9X[}ik0
catch(Exception e){e.printStackTrace ();} y+ZCuX
q=|0lZ$`V_
R404\XGL
} ;th]/ G
!YJ^BI
W=)wiRQm
public static void main(String[] args) 6"UL+$k
{ dS[="Set
new TestMethod(); H@R2mw
} fpK`
} -$J%.fdPs
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