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)); y_m+&Oe
} P&0eu
for(int i=0;i<nEndPos.length-1;i++) wI@87&
{ P j
nEndPos = nStartPos[i+1]; t/;2rIx>
} 3;>ls~4
nEndPos[nEndPos.length-1] = nFileLength; nCYkUDnZ
} b,'O|s]"Sc
} $d*9]M4
vT?^#
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//启动子线程 /l$enexSt
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yd;e;Bb7*
for(int i=0;i<nStartPos.length;i++) &jJu=6 U B
{ zsp%Cz7T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7P1Pk?pxy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aqON6|6K
nStartPos,nEndPos,i); v~mVf.j1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O},}-%G
fileSplitterFetch.start(); >V6t L;+
} s|\)Y*B`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KQr+VQdq>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $cSUB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R1zt6oY
nEndPos = " + nFileLength); yXU.PSG*
// fileSplitterFetch[nPos.length-1].start(); neFwxS?
oxxuw Dcl
bv4umL /
//等待子线程结束 {;{U@Z
//int count = 0; rI>x'0Go*
//是否结束while循环 pwFdfp
boolean breakWhile = false; c{=;lT
-`faXFW'
9L>?N:%5
while(!bStop) COw"6czX/
{ T8+[R2_
write_nPos(); i.E2a)
Utility.sleep(500); %axr@o[
breakWhile = true; ei5YxV6I
}5+^
H~FI@Cf$L
for(int i=0;i<nStartPos.length;i++) t'eaR-
{ 5_(\Cd<#
if(!fileSplitterFetch.bDownOver) Qj^Uz+b
{ Wj.t4XG!
breakWhile = false; QXb2jWz
break; L"b&O<No
} Bt<)1_
} S)U*1t7[
if(breakWhile) kp*v:*
break; I# tlaz#
-DkD*64wu
X$!fR >Zc
//count++; x17:~[c']
//if(count>4) Em!- W5*s
// siteStop(); E&8Nh J
} i)x0]XF
ov+{<0Q
Wep^He\:
System.err.println("文件下载结束！"); |u>V> PN
} 33~MP;
catch(Exception e){e.printStackTrace ();} uZld9u
} rD}g9?ut
'iW
CQ2vFg3+o
//获得文件长度 5M>h[Q"R
public long getFileSize() 9G[ DuYJI
{ d`/8Q9tQ
int nFileLength = -1; jG1(Oe;#
try{ M8-8T
URL url = new URL(siteInfoBean.getSSiteURL()); UV2W~g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ur+U#}
httpConnection.setRequestProperty("User-Agent","NetFox"); E`j' <#V!
cq[9#@ 4=
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int responseCode=httpConnection.getResponseCode(); li[[AAWVm
if(responseCode>=400) Jh.~]\u
{ ?;RY/[IX6
processErrorCode(responseCode); XHA|v^
return -2; //-2 represent access is error +JI,6)Ry
} %1 )c{7
dy+A$)gY<
5$ik|e^:y
String sHeader; 1KUjb@"
|pHlBzHj
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for(int i=1;;i++) ku,{NY f^Y
{ O[ z0+Q?6Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &KMI C
//Utility.log(in.readLine()); Lyc6nP;F
sHeader=httpConnection.getHeaderFieldKey(i); bhD-;Y!6;
if(sHeader!=null) !Q"L)%)'A
{ -Y524
if(sHeader.equals("Content-Length")) }aOqoi7w
{ 8Ay7I
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \HB fM&
break; F%V|Aa
} Il&FC
} a8TtItN
else &S(>L[)9
break; 62ru%<x=
} IN/$b^Um
} 4Wgzp51Aq!
catch(IOException e){e.printStackTrace ();} 9"^ib9M
catch(Exception e){e.printStackTrace ();} z*T41;b
#U-y<[ 3
F9LKO3Rh#u
Utility.log(nFileLength); =+_nVO*
2Rw<0.i|
P DY :?/
return nFileLength; At@0G\^
} rd&d~R6
$W|JQ h
,~cK]!:>s
//保存下载信息（文件指针位置） 6Mk#) ebM
private void write_nPos() ; s(bd#Q
{ sq=EL+=j
try{ b; of9hY
output = new DataOutputStream(new FileOutputStream(tmpFile)); Hx6ODj[-
output.writeInt(nStartPos.length); ]0'cdC
for(int i=0;i<nStartPos.length;i++) r??_2>Q
{ E"*E[>
// output.writeLong(nPos); D`QMlRzXy
output.writeLong(fileSplitterFetch.nStartPos); _b8KK4UR
output.writeLong(fileSplitterFetch.nEndPos); k(G6` dY
} @Nb/n
output.close(); <U$YJtEK
} 1M`>;fjYa
catch(IOException e){e.printStackTrace ();} <SJ6<'
catch(Exception e){e.printStackTrace ();} =p@2[Uo
} n`^jNXE
eTjPztdJbx
z(c8]Wu#
//读取保存的下载信息（文件指针位置） 9wCgJ$te
private void read_nPos() (P?|Bk[
{ \X\< +KU
try{ a)W|gx6Y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y 22Ai
int nCount = input.readInt(); pF6u3]
nStartPos = new long[nCount]; * 4J!@w
nEndPos = new long[nCount]; "tl{HM5u
for(int i=0;i<nStartPos.length;i++) JjZB!Lg=
{ Otu?J_d3
nStartPos = input.readLong(); |};d:LwX
nEndPos = input.readLong(); #qVvh3#g
} w&YUb,{Y
input.close(); ?J6Ek*E#
} #NyO'
catch(IOException e){e.printStackTrace ();} )7Hx<?P
catch(Exception e){e.printStackTrace ();} RNB-W%
} gm5%X'XL
KRGj6g+
9.xb-m7
private void processErrorCode(int nErrorCode) { (.@bT@
{ ;m] nl_vg
System.err.println("Error Code : " + nErrorCode); W2h*t"5W
} 78]*Jx>L
a9&[Qv5-/
\roJf&O }
//停止文件下载 pGU.+[|(
public void siteStop() UQkd$w<
{ r1q'+i
bStop = true; =~D[M)UO|
for(int i=0;i<nStartPos.length;i++) 8Mtd}{Fw*
fileSplitterFetch.splitterStop(); hTO5*5]0zP
m^BXLG:b
5vD\?,f E
} h)sT37
} 'r=2f6G>cP
//负责部分文件的抓取 W8`6O2
**FileSplitterFetch.java hwk] ;6[
*/ tWl')^
package NetFox; \a0{9Xx F
ir}*E=*
u0)O Fz
import java.io.*; r[):'ys,C
import java.net.*; =M:Po0?0E
fiC0'4.,
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public class FileSplitterFetch extends Thread { tMdSdJ8
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?$)a[UnqX
String sURL; //File URL <9H3d7%
long nStartPos; //File Snippet Start Position Q7pCF,;
long nEndPos; //File Snippet End Position Otr=+i ZI
int nThreadID; //Thread's ID :?EZ\WM7
boolean bDownOver = false; //Downing is over Lm!]m\LRZD
boolean bStop = false; //Stop identical ox<6qW
FileAccessI fileAccessI = null; //File Access interface C:&Sk\
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;*K;)C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XU<owk
{ h('5x,G%
this.sURL = sURL; !m=Js"
this.nStartPos = nStart; GYy8kp84
this.nEndPos = nEnd; 3,Z;J5VL4!
nThreadID = id; )y:M8((%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 K_t >T)K
} ]?}pJ28
\+Qd=,!i(
HQF@@
public void run() .mwW`D
{ VWd`06'BN'
while(nStartPos < nEndPos && !bStop) i\Yd_
{ 7H6Ge-u
jB9~'>JY
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try{ F@z%y'5 Z*
URL url = new URL(sURL); %d-WQwJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RwK6u-u#9
httpConnection.setRequestProperty("User-Agent","NetFox"); 1fJ~Wp @1
String sProperty = "bytes="+nStartPos+"-"; ~U7Bo(EJp
httpConnection.setRequestProperty("RANGE",sProperty); 3J8>r|u;1'
Utility.log(sProperty); ;j~%11
TUGD!b{
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InputStream input = httpConnection.getInputStream(); Qa2p34Z/
//logResponseHead(httpConnection); }#~E-N3x
|gk4X%o6
LB.B w
byte[] b = new byte[1024]; +F,])p4,]i
int nRead; p4\sKF8-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y] 9/Xr/
{ uDcs2^2l
nStartPos += fileAccessI.write(b,0,nRead); D'moy*E
//if(nThreadID == 1) rkh%[o9"/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .`u8(S+
} Bk~lM'
ZJFF4($qN
>^W6'Q$P<
Utility.log("Thread " + nThreadID + " is over!"); vEG7A$Z"
bDownOver = true; c9@3=6S/
//nPos = fileAccessI.write (b,0,nRead); }"RVUYU
} 4a!%eBhX"K
catch(Exception e){e.printStackTrace ();} SH"<f_
} um<$L
} r.u\qPT&
2u0B=0x
ETX>wZ
//打印回应的头信息 AL&<SxuP
public void logResponseHead(HttpURLConnection con) :%28*fl
{ jL)Y'
for(int i=1;;i++) 5Uhxl^c
{ 8.%wnH
String header=con.getHeaderFieldKey(i); V\n!?1{kdF
if(header!=null) uARkf'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N*PJ m6-
Utility.log(header+" : "+con.getHeaderField(header)); 3,!IV"_
else 247vU1
break; `6YN/"unfp
} ]m&Ss
} #5^OO ou|
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7N5M=f.DS(
public void splitterStop() 2cS94h
{ TZn5s~t
bStop = true; 2t0VbAO1{
} ] fA5D)/m<
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zLxuxf~4@
} [P6A$HC<
cJSwA&
.R4,fCN
/* TR `C|TV>
**FileAccess.java Zu~t )W
*//文件访问(定位，写) 2h}FotlO
package NetFox; "-5FUKI-
import java.io.*; qauvwAMuX
lA6{TH.x
&liFUP?
public class FileAccessI implements Serializable{ S,'ekWVD
0>;[EFL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7)>L#(N
RandomAccessFile oSavedFile; wpNb/U
long nPos; p Zxx
q+;lxR5D
cF iTanu
public FileAccessI() throws IOException 5ff5M=M
{ ;_ 1Rk&o!
this("",0); uTl"4;&j
} ,Cy&tRjR B
m<;MOS
ulEtZ#O{_
public FileAccessI(String sName,long nPos) throws IOException 3+C;zDKa
{ VVuNU"-
oSavedFile = new RandomAccessFile(sName,"rw"); f*m^x7
this.nPos = nPos; QD-Bt=S7l
oSavedFile.seek(nPos); "79b>
} >r4BI}8SK<
u2':~h?l
c*(=Glzn
public synchronized int write(byte[] b,int nStart,int nLen) V6Of(;r
{ b ts*qx&)
int n = -1; PKGqu,J,
try{ )1YGWr;ykS
oSavedFile.write(b,nStart,nLen); ;s4e8![o3
n = nLen; a@? Bv
} 4VA]S
catch(IOException e) dry%aT
{ v9gaRqi8
e.printStackTrace (); f7%g=0.F
} Tjj27+y*\
=*UVe%N4
y#O/Xw
return n; r$LU$F
} Fvnf;']q
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,6A/| K-
} '1G0YfG}n
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!l9#a{#6l
/* 6Tq2WZ}<'
**SiteInfoBean.java Pi%-bD/w
*/ # M Y4Mr
package NetFox; l`:-B'WM
An BM*5G
F=UW[zy/[
public class SiteInfoBean { COH.`Tv{*
#S|On[Q!
h`tf!MD]
private String sSiteURL; //Site's URL *@YQr]~ ;
private String sFilePath; //Saved File's Path {PL,3EBG
private String sFileName; //Saved File's Name y}W*P#BDO
private int nSplitter; //Count of Splited Downloading File Kc3/*eu;
k$,y1hH;f8
`y1,VY
public SiteInfoBean() @d^MaXp_P
{//nSplitter的缺省值为5 b#S-u }1PE
//default value of nSplitter is 5 YIl,8! z~
this("","","",5); %!L*ec%,
} OJ7y
%VrMlG4hx
2T"[$iH!7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) XpT})AV
{ a7]Z_Gk
sSiteURL= sURL; sJ_3tjs)
sFilePath = sPath; kPnuU!
sFileName = sName; ]/mRMm9"3h
this.nSplitter = nSpiltter; Yp$@i20
c[?&;# feV
1fh6A`c
} u/`x@u
2bpFQ8q
T zHR
public String getSSiteURL() :O*62olC5
{ ,^T0!k$
return sSiteURL; ZB,UQ~!Yr
} KeC&a=HL
YgkQF0+
%bhFl,tL
public void setSSiteURL(String value) >>>MTV f
{ ,0n=*o@W
sSiteURL = value; u z:@
} )Mw 3ZE92
7$:Jea
MV?sr[V-oP
public String getSFilePath() Wp=&nh
{ PE+{<[n
return sFilePath; ;BEX|wxn
} /<IXCM.
Mwd.S
71HrpTl1fw
public void setSFilePath(String value) WQY\R!+
{ z`|E0~{-
sFilePath = value; jx];=IC3tt
} %U&ztvR0C
]Ai!G7s8P
YZ5[#E@l
public String getSFileName() I8:G:s:
{ 'i8?]` T
return sFileName; 4"V6k4i5
} S)A;!}RK6
2ZQ|nwb7
+|spC
public void setSFileName(String value) ; 5!8LmZ0#
{ ;:ocU?
sFileName = value; $/P\@|MqYQ
} NJ!}(=1|K
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vP/sG5$x
public int getNSplitter() 1);E!D[
{ G)7J$4R
return nSplitter; hmtDw,j
} -"n8Wv
> ,P,{"
l65Qk2<YC
public void setNSplitter(int nCount) uulzJbV,K
{ )0 i$Bo
nSplitter = nCount; S >\\n^SbT
} yI$MqR
} ~ePtK~,dv
_v=zFpR
\1#!%I=.
/* hKFB=U
**Utility.java m\J"P'=
*/ 7e@Bkq0)
package NetFox; Zq\ p%AU9
LwEc*79
]4&B*]j
public class Utility { A,GJ6qp3
coc:$Sr%
P,SI0$Z
public Utility() ~DK=&hCd!
{ 0,[-4m
=zKbvwe%X
*", BP]]
} kv?j]<WN
)]m_ L$9
//线程睡眠 :X-\!w\
public static void sleep(int nSecond) <=!|U0YV
{ 05vu{>
try{ ou'|e"tI
Thread.sleep(nSecond); 4 {3< `
} 8*yky
catch(Exception e) tsqWnz=)
{ R{Qvpd$y
e.printStackTrace (); ogKd}qTov
} WevXQ-eKm
} qt#4i.Iu+
%p.hwgvnp
//日志 O7tL,)Vv
public static void log(String sMsg) 7)+%;|~
{ >R8eAR$N
System.err.println(sMsg); qy~@cPT
} 9mH+Ol#(
l j*J|%~
O(f&0h !
public static void log(int sMsg) 6dX l ny1H
{ U})Z4>[bvt
System.err.println(sMsg); [=I==?2`X
} p9$=."5
} &T/}|3S
HA%r:Px
xDBHnr}[
/* al:c2o
**TestMethod.java Q\<^ih51
*/ }x}JzA+2
package NetFox; Oe%jV,S|V
wa4(tM2
]gGCy '*)
public class TestMethod { $5m_)]w4a
jF%[.n[BU
LC:bHM,e
public TestMethod() N?;5%pG <
{ ///xx/weblogic60b2_win.exe B[Fuyy?
try{ eFeWjB'<7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #NLLlEE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1)f~OL8o
SiteFileFetch fileFetch = new SiteFileFetch(bean); y[@<goT
fileFetch.start(); k/ ZuFTN
} yS:1F PA$_
catch(Exception e){e.printStackTrace ();} 2Md'<.
IKV:J9
ZIrJ"*QO=
} ewcgg
kaj6C_k|
';bovh@*
public static void main(String[] args) !56gJJ-r
{ R]{AJ"p
new TestMethod(); U1^R+ *yp
} `L=$,7`
} R7 *ek_
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