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)); ewym1}o
} |AC6sfA+
for(int i=0;i<nEndPos.length-1;i++) VGB-h'
{ VKNp,Lf
nEndPos = nStartPos[i+1]; ~{P:sjsU
} Je@kiE
nEndPos[nEndPos.length-1] = nFileLength; Y1WHy*s?
} =U c$D*
} C.( yd$,
f1J%]g!
'bPk'pj9
//启动子线程 r@yD8D \
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G5;V.#"Z[
for(int i=0;i<nStartPos.length;i++) S/fW/W*/}
{ .jargvAL*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;NP[_2|-,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \lW_f{X)
nStartPos,nEndPos,i); 79wLT\&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vd(dNu&,<
fileSplitterFetch.start(); n/AW?'
} p-Pz=Cx-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :3 y_mf>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <sc\EK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [@|be.g
nEndPos = " + nFileLength); "wINBya'M
// fileSplitterFetch[nPos.length-1].start(); 5VKcV&D
9n 6fXOC
jtCZfFD?
//等待子线程结束 2( _=SfQ
//int count = 0; Um\0i;7 ~4
//是否结束while循环 8YKQItK
boolean breakWhile = false; (Q_2ODKo
K$ AB} Fvc
sf)W~Lx5a
while(!bStop) yl/a:Q
{ R8 jovr
write_nPos(); PQ3h\CL1n
Utility.sleep(500); 1eD.:_t4
breakWhile = true; M(2`2-/xh
C_Gzv'C"L
{R8=}Qo
for(int i=0;i<nStartPos.length;i++) fGTOIi@#
{ )x[HuIRaa
if(!fileSplitterFetch.bDownOver) sOz sY7z3Z
{ I7zn>^0}
breakWhile = false; SK-W%t
break; SX_4=^
} o\goE^,aeR
} 5r7h=[N
if(breakWhile) H`el#tt_
break; anC+r(jjg9
W+hV9
M _(2sq
//count++; o%qkqK1
//if(count>4) ;{Jb6'K1h
// siteStop(); GO~k '
} "lrA%~3%[P
l;0y-m1
/< QSe
System.err.println("文件下载结束！"); bjzx!OCpV
} |7c`(.
catch(Exception e){e.printStackTrace ();} tN2 W8d
} "-0;#&!
j|(:I:]
Vhph`[dC{
//获得文件长度 aS/`A
public long getFileSize() IN_gF_@%
{ FUqt)YHi
int nFileLength = -1; Xm@aYNV
try{ &h(g$-l?[
URL url = new URL(siteInfoBean.getSSiteURL()); DY.58IHg1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s#P:6]Ar
httpConnection.setRequestProperty("User-Agent","NetFox"); JJ-i_5\q
km4g}~N</
<+q$XL0
int responseCode=httpConnection.getResponseCode(); U&Ab#m;
if(responseCode>=400) *~;8N|4<
{ _lT0Hu
processErrorCode(responseCode); R@n5AN(
return -2; //-2 represent access is error Mpm#GdT
} \O? u*
>UWStzH<
+nQ!4
String sHeader; }p{;^B
+'%\Pr(
1Is%]6
for(int i=1;;i++) choL%g}
{ G#lg|# -#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); X+at%L=
//Utility.log(in.readLine()); }p*?1N
sHeader=httpConnection.getHeaderFieldKey(i); <4f,G]UH_
if(sHeader!=null) *B{-uc3o
{ j+Zt.KXjT
if(sHeader.equals("Content-Length")) >BJ}U_ck
{ EneAX&SG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); MA6P"?
break; [#Fg\2bq_y
} @yKZRwg
} r<|nwFJ
else y||@?Y
break; 0'@u!m?
} g@u;Y5
} Tq#<Po $
catch(IOException e){e.printStackTrace ();} N7pt:G2~%
catch(Exception e){e.printStackTrace ();} -|[~sj-p
,CKvTxz0
7E\gxQ(vU
Utility.log(nFileLength); bpp*
u~}%1
Lzz)n%y5
return nFileLength; waQtr,m)
} ~p^7X2% !
$?$9y^\
@/(@/*+"
//保存下载信息（文件指针位置） ppFYc\&=
private void write_nPos() y\Dn^
{ :x+ig5
try{ <m1sSghg
output = new DataOutputStream(new FileOutputStream(tmpFile)); 045\i[l=
output.writeInt(nStartPos.length); ymkR!
for(int i=0;i<nStartPos.length;i++) J#(,0h
{ $}4K`Iu
// output.writeLong(nPos); 5[<F_"x
output.writeLong(fileSplitterFetch.nStartPos); W>:kq_gT
output.writeLong(fileSplitterFetch.nEndPos); }$:#+ (17
} I%i:)6Un-y
output.close(); j6og3.H-
} QT;Va#a
catch(IOException e){e.printStackTrace ();} 6l[G1KkV
catch(Exception e){e.printStackTrace ();} 9FNwpL'C
} Q"'V9m7 i
]>vf9]
C fSl 54
//读取保存的下载信息（文件指针位置） x< S\D&
private void read_nPos() 17i$8
{ H/`G
try{ C$K+=jT
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T`Ro)ORC#
int nCount = input.readInt(); (H1lqlVWV#
nStartPos = new long[nCount]; sX5sL
nEndPos = new long[nCount]; Yw[{beo
for(int i=0;i<nStartPos.length;i++) "uhV|Lk*7
{ phS>T
nStartPos = input.readLong(); BkV(81"C
nEndPos = input.readLong(); L~ 2q1
} gY%&IHQ'
input.close(); ;Z4o{(/zU
} 4oN${7k0
catch(IOException e){e.printStackTrace ();} "Y(^F bs
catch(Exception e){e.printStackTrace ();} 48k7/w\
} ]?# #))RUS
`VXZ khm
^Xa*lR 3
private void processErrorCode(int nErrorCode) O%VA)<
{ $l#{_~ "m7
System.err.println("Error Code : " + nErrorCode); CpSK(2j
} e{JVXc[D
hb<k]-'!
ArL-rJ{}
//停止文件下载 fCr\u6Tb
public void siteStop() /6jGt'^U
{ 6y9C@5p}B
bStop = true; u?Z <n:
for(int i=0;i<nStartPos.length;i++) ?rQc<;b
fileSplitterFetch.splitterStop(); /W0E(8:C)
hv{87`L'K(
z{' 6f@]
} @`Wt4<
} u{P~zyx
//负责部分文件的抓取 /ISLVp%H
**FileSplitterFetch.java hk.yR1Y|
*/ SXh?U,5u
package NetFox; k{{hZ/om
p_9g|B0D
5Edo%Hd6
import java.io.*; !3?yG
import java.net.*; -_HRqw,Z0
h(|;\~
5pmQp}}R
public class FileSplitterFetch extends Thread { c(E,&{+E
wsI5F&R,
'{CWanTPi
String sURL; //File URL `{<JC{yc?
long nStartPos; //File Snippet Start Position [n!x&f8Xh
long nEndPos; //File Snippet End Position M=6G:HHY
int nThreadID; //Thread's ID jJc07r']
boolean bDownOver = false; //Downing is over ez+yP,.#
boolean bStop = false; //Stop identical NFV_+{X\
FileAccessI fileAccessI = null; //File Access interface 3u4:l
V pH|R
^X^,>Z|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y.X4*B
{ 1xIFvXru
this.sURL = sURL; %!yxC
this.nStartPos = nStart; s{B_N/^
this.nEndPos = nEnd; vU{jda$$#
nThreadID = id; p&uCp7]U
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &8afl"_~
} T(gg>_'jh
%:%MUdl6
j<@fT ewZ
public void run() BJ2Q2WW
{ d9|T=R
while(nStartPos < nEndPos && !bStop) ~Zu}M>-^c,
{ /0l-mfRr
v?}pi
@f%wd2
try{ wM0E%6 P
URL url = new URL(sURL); aTX]+tBoe
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t%:G|n Sz
httpConnection.setRequestProperty("User-Agent","NetFox"); @~hz_Nm@8
String sProperty = "bytes="+nStartPos+"-"; gLV^Z6eE
httpConnection.setRequestProperty("RANGE",sProperty); LjCykk
Utility.log(sProperty); <0>[c<{V<
{n6\g]p3
m3B\)2B
InputStream input = httpConnection.getInputStream(); h)P]gT0f/
//logResponseHead(httpConnection); a 1NCVZ
ze ?CoDx2
rCkYfTYI
byte[] b = new byte[1024]; p[b7E`7
int nRead; T*8_FR<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m qpd
{ uZ-`fcCjD
nStartPos += fileAccessI.write(b,0,nRead); r.9 $y/5
//if(nThreadID == 1) \1~I04'=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $=lJG(2%
} zQn//7#-G
Ae.]F)w_\
tfsh!)u?
Utility.log("Thread " + nThreadID + " is over!"); s 8Jj6V
bDownOver = true; rrYp'L
//nPos = fileAccessI.write (b,0,nRead); VSx%8IM+X
} ~ J%m
catch(Exception e){e.printStackTrace ();} #c:9V2
} b6]e4DL:R
} )S#j.8P'B
+H[Q~P8'[
-GK'V
//打印回应的头信息 8dlInms
public void logResponseHead(HttpURLConnection con) > e;]mU`,
{ aam1tm#Q
for(int i=1;;i++) q;KshpfRMD
{ ?F9hDLX
String header=con.getHeaderFieldKey(i); rpx0|{m
if(header!=null) juR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HuK Aj
Utility.log(header+" : "+con.getHeaderField(header)); BSjbnnW}"
else P&h/IBA_
break; ~T;K-9R
} )ynA:LXx
} zo/0b/lQ
Q.*'H_Y
s8{-c^G:R
public void splitterStop() 38<~R
{ AUu5g
bStop = true; OCvml 2 vP
} N"&$b_u[
ZWov_
anpJAB:1
} B#;s(O
,o4r,.3[s
r*c82}tc
/* 9UB??049z
**FileAccess.java sb8z_3
*//文件访问(定位，写) S.qk%NTTD
package NetFox; wVlSjk
import java.io.*; F]hx
2LtU;}7s
=ZFcxGo
public class FileAccessI implements Serializable{ ](]*]a4ss
yLV2>kq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 []^PJ
RandomAccessFile oSavedFile; yp( ?1
long nPos; k];L!Fj1
'O!Z:-qE
.LWOM8)
public FileAccessI() throws IOException |^ 2rtI
{ vcaBL<io
this("",0); -lnTYxo+]^
} !pG+Ak?
*2w_oKE'+5
8L%%eM_O
public FileAccessI(String sName,long nPos) throws IOException f0:EQYYZ
{ #nxER
oSavedFile = new RandomAccessFile(sName,"rw"); WHZe)|n
this.nPos = nPos; p,3go[9X:R
oSavedFile.seek(nPos); *>?):-9"6N
} B:.;,@r]
;5,`Jpca
?{y:s!!
public synchronized int write(byte[] b,int nStart,int nLen) xc:`}4
{ 9_g>BI;"8
int n = -1; azz#@f1
try{ FKDamHL<
oSavedFile.write(b,nStart,nLen); 48R]\B<R{
n = nLen; O('i*o4!}
} !gD 3CA
catch(IOException e) b(+w.R(+Ti
{ w0q?\qEX
e.printStackTrace (); ?,A}E|jZ
} @5<]W+jk4
O>)n*OsS
Pu/-Qpqh
return n; ~(Ih~/5\^
} FZeN,
c,g]0S?gu
b/a?\0^
} ;EE{~
+MOe{:/6
I;bg?RsF
/* w>/pQ6=OFR
**SiteInfoBean.java ?15POY ?Z
*/ $9j>VGf=
package NetFox; ~Q.8 U3"
o O{|C&A
%XDip]+rb
public class SiteInfoBean { XL"v21X
"-~D!{rS
iXr`0V
private String sSiteURL; //Site's URL 2@=cqD7x
private String sFilePath; //Saved File's Path %^Q@*+{:f
private String sFileName; //Saved File's Name 3:02`;3
private int nSplitter; //Count of Splited Downloading File GlV-}5W
pw(U< )
]$XBd{\D{
public SiteInfoBean() A{{q'zb!
{//nSplitter的缺省值为5 )cv0$
//default value of nSplitter is 5 'Wx\"]:
this("","","",5); \\E_W9.u
} |}]JWsuB
)Rm 'YmO
{Q#Fen ;y|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) eEg1-
{ D>"{H7mY
sSiteURL= sURL; Wq[=}qh~
sFilePath = sPath; r(?'Yy
sFileName = sName; Wf+Cc?/4
this.nSplitter = nSpiltter; g-{<v4NGI
4cVs(`g^
7E\K!v_
} D x>1y
T9XW%/n
/pSUn"3
public String getSSiteURL() )N%1%bg^-
{ !4b;>y=m
return sSiteURL; TS~Y\Cp
} k:+)$[t7
&EbD.>Ci
qMW%$L\HA
public void setSSiteURL(String value) ^8f|clw"
{ c?V*X-
sSiteURL = value; ]y)R C-N
} 9L)&n.t1
[M8qU$&?]
FRJ:ym=E
public String getSFilePath() @88z{
{ 4Q`=t&u
return sFilePath; 2gC&R1H
} U d=gdsL
"k_n+cH%
Mh-*5Rx
public void setSFilePath(String value) B3g82dm
{ 6{Cu~G{]N
sFilePath = value; 9B?t3:
} w7*b}D@65\
tr9_bl&z
*nUpO]
public String getSFileName() e$xv[9
{ 8ZDqqz^C0
return sFileName; bTy'5"
} G+QNg.pH
6UzT]"LR;
>Wr
public void setSFileName(String value) pb2{J#
{ UV *tO15i
sFileName = value; P20]>Hg
} nm:let7GB
{p lmFV
[:hy
public int getNSplitter() +<9q]V
{ )(|0KarF
return nSplitter; g]PLW3
} 5 1CU@1Ie
$X<<JnsK
@,>=X:7
public void setNSplitter(int nCount) pTV@nP
{ "<n"A7e
nSplitter = nCount; |uBot#K|
} :+dWJNY:
} J ]l@ r
*a0I Z
`S~@FX
/* 5z(>4d!
**Utility.java c7TWAG_+
*/ p7=^m>Z6
package NetFox; }AH|~3|D
(.nJT"&
4kY{X%9
public class Utility { YT%SCaU
4[V6so0
CO)b'V,
public Utility() U%PMV?L{
{ E#X!*q&
s:Ql](/B#
vJjj+:
} F]&J%i F[
;KZ2L~ THG
//线程睡眠 @Q1F#IU
public static void sleep(int nSecond) d8q$&(]<
{ XJ1nhE
try{ rM~IF+f0XD
Thread.sleep(nSecond); )yH#*~X_
} D~`YRbv
catch(Exception e) UmI@":|-
{ sbiDnRf
e.printStackTrace (); ~x^+OXf!^g
} cZK?kz_Y
} WxP4{T* <
AJ1$$c
//日志 u'n%BVt
public static void log(String sMsg) C00*X[p
{ {ZYCnS&?CL
System.err.println(sMsg); :V1ZeNw
} 0c;"bA0>Sx
H&Lbdu~E
zmS-s\$,
public static void log(int sMsg) *oJ>4S
{ $MEbePxe
System.err.println(sMsg); ['YRY B
} |0pBBDw
} OZ]3OL,
(8X8<>w~
#Q)w$WR
/* 7Sv5fLu2
**TestMethod.java 8o5^H>
*/ yaGVY*M0
package NetFox; 7Qztc?XK
L=Jk"qWV0
(C[S?@S
public class TestMethod { (#Kvm
G uI sM
J3JRWy@?P
public TestMethod() Q-%=ZW Z
{ ///xx/weblogic60b2_win.exe 'eXw`kw(
try{ k <Sa<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MZF ;k$R
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !g:G{b
SiteFileFetch fileFetch = new SiteFileFetch(bean); IIEU{},}z
fileFetch.start(); rca"q[,
} [GT1,(}. Z
catch(Exception e){e.printStackTrace ();} 5DBd [u3
WC&Ltw8
e ^&8x
} Z#V\[
0#nXxkw
Y##P9^zH1
public static void main(String[] args) *iN]#)3>
{ @8d})X33
new TestMethod(); _C#()#
} ?S7:KnU>K
} qq{N; C
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