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)); K ze?@*
} fp' '+R[
for(int i=0;i<nEndPos.length-1;i++) }=[p>3Dd
{ nK1eh@a9Qv
nEndPos = nStartPos[i+1]; 0K%okq|n
} NPT-d
nEndPos[nEndPos.length-1] = nFileLength; DM^0[3XuV5
} R| ?Q&F_$
} ~~W.]>f
djdTh +>28
WNGX`V,d
//启动子线程 >Ku4Il+36
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :?6HG_9X
for(int i=0;i<nStartPos.length;i++) ~)U50.CH
{ &Hb%Q! ^Kb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "lh4Vg\7n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), J=` 8
nStartPos,nEndPos,i); NN*L3yx
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;llPM`)
fileSplitterFetch.start(); }?s-$@$R
} 23gN;eD+m6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FEjO}lTK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *7xcwjeP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oy^-?+
nEndPos = " + nFileLength); $hhXsu=
// fileSplitterFetch[nPos.length-1].start(); 0cS$S Mn{
U>2KjZB
9 C[~*,qx
//等待子线程结束 GW,EyOE+~
//int count = 0; NUV">i.(
//是否结束while循环 nn7LL+h
boolean breakWhile = false; Q,KNZxT,q
6!\V|
fDy*dp4z
while(!bStop) uy{O
{ 46>rvy.r
write_nPos(); zPaubqB
Utility.sleep(500); CvU$Fsb
breakWhile = true; ?Y4 +3`\x
tbS hSbj
Cn~VJ,l g
for(int i=0;i<nStartPos.length;i++) J@5iD
{ YSP\+ZZ
if(!fileSplitterFetch.bDownOver) ]Dq6XR
{ !85bpQ.
breakWhile = false; d{S'6*`D
break; c4fH/-
} cp`Jep<T
} $${I[2R)
if(breakWhile) dc)%5fV\
break; 7{m>W!
^*ZaqMA
:uCwWv
//count++; EO!,rB7I
//if(count>4) t2dsYU/
// siteStop(); sX1DbEjj[o
} 9JA@m
1-y8Hy_a2
6>]_H(z7
System.err.println("文件下载结束！"); [G}dPXD
} wn[)/*(,$(
catch(Exception e){e.printStackTrace ();} L$PbC!1
} `+,?%W)
L`nW&;w'
5A0]+)5E8
//获得文件长度 j\ y!
public long getFileSize() t%qep|
{ =yod
int nFileLength = -1; ^Q8yb*MN
try{ UR'[?
URL url = new URL(siteInfoBean.getSSiteURL()); u@_|4Bp,"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M/o?D <'
httpConnection.setRequestProperty("User-Agent","NetFox"); BN9e S
=8]`-(
x=DxD&I!J
int responseCode=httpConnection.getResponseCode(); Bp^LLH
if(responseCode>=400) _lv{8vf1B
{ vMz|'-rm$
processErrorCode(responseCode); ZXnacc~s
return -2; //-2 represent access is error u"0{) ,
} al[^pPKZ
i@rtt M
Mq0MtC6-
String sHeader; ._rPM>B?
Qder8I
mx9vjWfy
for(int i=1;;i++) s@Q7F{z
{ p"0#G&-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1 uU$V =
//Utility.log(in.readLine()); ?Bu*%+
sHeader=httpConnection.getHeaderFieldKey(i); +R*DE5dz
if(sHeader!=null) dj0%?g>
{ 9`f@"%h
if(sHeader.equals("Content-Length")) $FPq8$V
{ (.#nl}fA
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X_78;T)uA
break; J1w[gf]J
} g *,O
} KdoI
else a>v *
break; m"!SyN}&9?
} d|R-K7 ~~
} x;?8Zr
catch(IOException e){e.printStackTrace ();} y.Z_\@
catch(Exception e){e.printStackTrace ();} l= {Y[T&
j@4MV^F2c
_[[0rn$
Utility.log(nFileLength); F3bTFFt
7hk<{gnr
^Laqq%PI
return nFileLength; e|k]te
} $OZ= L
gAqK/9;
63E6nW M
//保存下载信息（文件指针位置） $#rkvG_w
private void write_nPos() qm=U<'b^
{ h3`}{ w
try{ ,>B11Z}PH
output = new DataOutputStream(new FileOutputStream(tmpFile)); Z )c\B
output.writeInt(nStartPos.length); |^1g*fy?
for(int i=0;i<nStartPos.length;i++) qm_l# u6
{ rO#w(]
// output.writeLong(nPos); jRg/N_2'2
output.writeLong(fileSplitterFetch.nStartPos); i|{psA
output.writeLong(fileSplitterFetch.nEndPos); ZLzc\>QX
} [63\2{_^v
output.close(); 4. R(`#f
} HGYTh"R
catch(IOException e){e.printStackTrace ();} >az~0PeEL
catch(Exception e){e.printStackTrace ();} =][ )|n
} RI*n]HNgy+
5 tKgm/
O|t>.<T?
//读取保存的下载信息（文件指针位置） IR${a)
private void read_nPos() aL:|Dr3SX
{ D?dBm
try{ !H\;X`W|~D
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1 iox0
int nCount = input.readInt(); 3@":&
nStartPos = new long[nCount]; AUD)=a>
nEndPos = new long[nCount]; @XJ7ff&
for(int i=0;i<nStartPos.length;i++) n$2oM5<
{ WK$\#>T
nStartPos = input.readLong(); 3VLwY!2:
nEndPos = input.readLong(); ?kR1T0lKkE
} NFTv4$5d
input.close(); rXW.F'=K6
} a{xJ#_/6
catch(IOException e){e.printStackTrace ();} qy'-'UlIr
catch(Exception e){e.printStackTrace ();} K9zr]7;th
} AE:(:U\
iZG-ca
YC1Bgz
private void processErrorCode(int nErrorCode) \Vme\Ke*v)
{ |tAkv
System.err.println("Error Code : " + nErrorCode); )p>Cf_[.
} v]M:HzP
;U3:1hn
yP7b))AW9
//停止文件下载 kn}^oRT
public void siteStop() GTLS0l)
{ '1D$ ;
bStop = true; 1 3]e< '
for(int i=0;i<nStartPos.length;i++) ))AxU!*.
fileSplitterFetch.splitterStop(); MiZ<v/L2
ow'G&<0b
HrE,K\^
} )n)AmNpq
} X{x(p
//负责部分文件的抓取 ;h1hz^Wq
**FileSplitterFetch.java +rv##Z
*/ }<~(9_+
package NetFox; <%YW/k"o
`<g]p-=":
PPl o0R
import java.io.*; T'}kCnp
import java.net.*; |fKT@2(
^##j {h7
a]*{!V{$i
public class FileSplitterFetch extends Thread { x_~_/&X5
WOn<JCh]
curYD~7
String sURL; //File URL oaQW~R`_
long nStartPos; //File Snippet Start Position oz=V|7,
long nEndPos; //File Snippet End Position )Lz =[e
int nThreadID; //Thread's ID xS UpVK
boolean bDownOver = false; //Downing is over 2V]a+Cgk
boolean bStop = false; //Stop identical \i+AMduAo
FileAccessI fileAccessI = null; //File Access interface EPJ>@A>;D
`V9bd}M%~;
H<|}pZ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (-$5YKm
{ bVz<8b6h'-
this.sURL = sURL; +c/!R|h=S
this.nStartPos = nStart; 693"Pg8b
this.nEndPos = nEnd; 2->Lz
nThreadID = id; 8SU0q9X.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0uD3a-J
} 'Y @yW3K
S(CkA\[rz
SZXSVz0j
public void run() 6:wk=#w
{ rmggP(
while(nStartPos < nEndPos && !bStop) 2pmj*Y3"8
{ K&&T:'=/
3ibQbk
{X<g93
try{ j5DCc,s
URL url = new URL(sURL); qeFaY74S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8o+:|V~X
httpConnection.setRequestProperty("User-Agent","NetFox"); 7HVENj_b+M
String sProperty = "bytes="+nStartPos+"-"; 8?8V;
httpConnection.setRequestProperty("RANGE",sProperty); <lR:^M[v5<
Utility.log(sProperty); a>l,H#w*vW
Tv1oy%dK
sSfP.R
InputStream input = httpConnection.getInputStream(); L~f~XgQ
//logResponseHead(httpConnection); Dl.UbH }=
a&0g0n6
pq r_{
byte[] b = new byte[1024]; cBqbbZyUk
int nRead; d BB?A~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c/ImK`:)4a
{ cz,CL/rno
nStartPos += fileAccessI.write(b,0,nRead); mxZ+r#|di
//if(nThreadID == 1) 842v^ 2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q]yw",muT
} !U:&8Le
)C"ixZ>2xQ
sCw>J#@2>
Utility.log("Thread " + nThreadID + " is over!"); 7k,BE2]"
bDownOver = true; #w%-IhP
//nPos = fileAccessI.write (b,0,nRead); vE,^K6q0`
} S`YT"|~
catch(Exception e){e.printStackTrace ();} Csy$1;"A
} @5wc 3y
} _cJ)v/]
N$Ad9W?T
5.ab/uk;M
//打印回应的头信息 QY4;qA
public void logResponseHead(HttpURLConnection con) &k,DAx`rN;
{ ECi;o1hda
for(int i=1;;i++) 7w2$?k',-
{ V-7l+C5
String header=con.getHeaderFieldKey(i); uvJHkAi
if(header!=null) tz2=l.1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [KgO:},c
Utility.log(header+" : "+con.getHeaderField(header)); Z[w}PN,xV
else d)V8FX,t
break; uWKmINjv'
} ;<m*ASM.3
} .]h/M,xg
u; KM[FmK
LDEc}XXb
public void splitterStop() ~b*]jZwT
{ /0qbRk i
bStop = true; YFS6YA
} riOaqV
MvZa;B
L,.~VNy-
} jZ-s6r2=
q/zU'7%@
$%cHplQz5
/* i,^3aZwJ'
**FileAccess.java 6\I^]\YO
*//文件访问(定位，写) $adZ|Q\
package NetFox; {|>Wwa2e
import java.io.*; XQn1B3k+
N,K/Ya)1
VQqBo~
public class FileAccessI implements Serializable{ G\F>*
ssLswb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >w<w*pC
RandomAccessFile oSavedFile; @%x2d1FS
long nPos; nS3Aadm
d/yF}%0QI
NjZ~b/
public FileAccessI() throws IOException ^wWbW&<Tg
{ ws9IO ?|&G
this("",0); X uE: dL?
} 1|4,jm$
3%5YUG@
(eU4{X7
public FileAccessI(String sName,long nPos) throws IOException xE@/8h
{ So!=uYX
oSavedFile = new RandomAccessFile(sName,"rw"); 2`riI*fQ
this.nPos = nPos; Wgh@XB
oSavedFile.seek(nPos); WtZI1`\qe
} 1N(1h D
8u~
:p}8#rb
public synchronized int write(byte[] b,int nStart,int nLen) MuOKauYa
{ 3%?tUt
int n = -1; }~+,x#
try{ #at`7#K@
oSavedFile.write(b,nStart,nLen); T 'c39
n = nLen; B2j1GJEO
} -c]AS[(
catch(IOException e) 9x@|%4Zm"
{ s*la`(x
e.printStackTrace (); l[:Aq&[o3
} >-N(o2j3
M{5AQzvs
~x8nC%qPvq
return n; pAatv;Ex
} "&k(lQ4
#PD6LO
<9ucpV
} k2v:F
:1UMA@HP
8lpAe0p(Z
/* ;_"|#
**SiteInfoBean.java ?nW>'z
*/ T#-;>@a}
package NetFox; la+Cra&xL
mF\!~ag|
a)ry}E =f
public class SiteInfoBean { 4{F1GW
Kb(11$U
TC/c5:)]
private String sSiteURL; //Site's URL =D$ED^W
private String sFilePath; //Saved File's Path DBHy%i
private String sFileName; //Saved File's Name {7goYzQsi%
private int nSplitter; //Count of Splited Downloading File 4Wiy2
<v0`r2^S{-
RX>P-vp
public SiteInfoBean() 0uDDaFS
{//nSplitter的缺省值为5 #gV n7wq
//default value of nSplitter is 5 I2*rtVAP'j
this("","","",5); zw+aZDcV(
} q_.fVn:!
d:';s~
sRD fA4/TF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) RJ3oI+gI
{ .^{%hc*w4
sSiteURL= sURL; WChP,hw
sFilePath = sPath; hNN[djR
sFileName = sName; /dYv@OU?
this.nSplitter = nSpiltter; l@B9}Icq
V,_m>$Mo
)6)bI.BY
} W\kli';jyC
y,nmPX?]n
VQla.Y
public String getSSiteURL() V_SH90@)+
{ z/{X{+Z
return sSiteURL; 2DCQ5XewYe
} 4MS<t FH)
C")genMH
)cJ>&g4]
public void setSSiteURL(String value) vt#;j;liG
{ tNTSy=
sSiteURL = value; YGyv)\
} ps 3)d
3 39q%j$
bGWfMu=n
public String getSFilePath() hN'])[+V
{ Tsg9,/vXM
return sFilePath; )SmnLvL
} ^OY]Y+S`Ox
+%W8Juu
~(d {j}M>
public void setSFilePath(String value) 1/Ts .\K3
{ rz"$zc.)
sFilePath = value; 5YD~l(,S1]
} +Dy^4p?o
iT-coI
*V6| FU
public String getSFileName() '{d@Gc6.
{ r9@=d
return sFileName; EraGG"+
} dgw.OXa
y'_8b=*
X.t4;
public void setSFileName(String value) q?(] Y*
{ Yb+A{`
sFileName = value; 3%Y:+%VE
} @z@%vr=vX
D!&(#Vl _
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public int getNSplitter() k]@]a
{ A;TP~xq\
return nSplitter; Nwi|>'\C
} yn62NyK
lgOAc,
j<<d A[X
public void setNSplitter(int nCount) FO2e7p^Q
{ vQEV,d1
nSplitter = nCount; Tz]R}DKB&
} -* ,CMw
} $O%{l.-O
nYyhQX~]B
rpT.n-H>%A
/* L80(9Y^xn
**Utility.java ~Bzzu %S
*/ p>B2bv+L
package NetFox; 8 t5kou]h
11=$]K>
'X?xn@?
public class Utility { xl\Kj2^
$m4-^=
x)::^'74
public Utility() ~K;QdV=YX
{ ":Dm/g
iQ)ydY a
;m(iKwDt
} sl]<A[jR
Y9+_MxC"
//线程睡眠 WTvUz.Et
public static void sleep(int nSecond) 4yl{:!la
{ i>F=XE
try{ 3P cVE\GN
Thread.sleep(nSecond); }|P3(*S
} .hl_zc#
catch(Exception e) bNea5u##
{ Aedf (L7\
e.printStackTrace (); xVm-4gB
} _;1{feR_
} d?2V2`6
Y %JQ
//日志 V'vR(Wx
public static void log(String sMsg) AcH-TIgM/
{ H9cPtP~a)
System.err.println(sMsg); @]=40Yj~w
} WgtLKRZ\
$]2)r[eA)
Y2H-D{a27
public static void log(int sMsg) r\Nfq(w
{ CXlbtpK2k
System.err.println(sMsg); qkb'@f=
} NX @FUct;
} PMzPj,
(`tRJWbdz
^#/FkEt7bp
/* %MHb
**TestMethod.java U&5*>fd=
*/ Kgbm/L0XR*
package NetFox; XjX
/)P}[Q4
AYts &+
public class TestMethod { isQ(O
'YL[s
FwCb$yE#M
public TestMethod() *3GV9'-P
{ ///xx/weblogic60b2_win.exe (f#(B2j
try{ =*mT{q@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~Z\:Nx
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U ZM #O
SiteFileFetch fileFetch = new SiteFileFetch(bean); j|eA*UE
fileFetch.start(); *r7vDc
} 1\.$=N
catch(Exception e){e.printStackTrace ();} x$Dq0FX!%_
;a:H-iC
u^80NR
} tdy2ZPVtTV
mDB
V>Wk\'h
public static void main(String[] args) \/a6h
{ r* *zjv>
new TestMethod(); M^FY6TT4O
} o96C^y{~S
} "W|A^@r}
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