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)); ?b (iWq
} !+GYu;_
for(int i=0;i<nEndPos.length-1;i++) T8XrmR&?PX
{ C= ~c`V5>r
nEndPos = nStartPos[i+1]; tn]nl!_@
} U'fP
nEndPos[nEndPos.length-1] = nFileLength; 7'G;ijx
} J2bvHxb Rd
} j#l=%H
X3.zNHN5
0a~t
//启动子线程 nf.Ox.kM)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -@pjEI
for(int i=0;i<nStartPos.length;i++) cHjQwl
{ )PX VR T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -'! J?~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 77P\:xc
nStartPos,nEndPos,i); <J/ =$u/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ma.84~m
fileSplitterFetch.start(); i?x gV_q;
} mMAN*}`O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I|Oco?Q"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }Q\%tZC#T
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q~ H>rC(\
nEndPos = " + nFileLength); x/*lNG/
// fileSplitterFetch[nPos.length-1].start(); oz)[-
"H-s_Y#
dljE.peL
//等待子线程结束 3:)z+#Uk6
//int count = 0; ARKM[]
//是否结束while循环 2|nm> 4
boolean breakWhile = false; @N=vmtLP
hFrMOc&
"-~7lY%
while(!bStop) |5&+VI
{ kwI``7g8*e
write_nPos(); >Bt82ibN
Utility.sleep(500); 1[FN: hm
breakWhile = true; 5^B79A"}
nV'1 $L#
O2w-nd74U
for(int i=0;i<nStartPos.length;i++) zF1!a
{ Abc{<4 z0?
if(!fileSplitterFetch.bDownOver) [9m3@Yd'
{ AGlBvRX7e
breakWhile = false; G@]3EP
break; Hfcpqa
} oaIk1U;g
} ~k"+5bHa*
if(breakWhile) '6so(>|
break; g'"~'
LrB 0x>
x~5uc$
//count++; R~vGaxZ$
//if(count>4) ~Amq1KU*Z
// siteStop(); BoD{fg
} 2HX/@ERhmu
-l^<[%
j*{0<hZb}
System.err.println("文件下载结束！"); !~ox;I}S
} ;Afz`Se1@
catch(Exception e){e.printStackTrace ();} p~D}Iyww1_
} djd/QAfSC
PDNl]?
VYk:c`E
//获得文件长度 J9^NHU
public long getFileSize() ]Q^)9uE\D
{ Cf% qap#
int nFileLength = -1; YT\`R
try{ U3(+8}Q
URL url = new URL(siteInfoBean.getSSiteURL()); =[B\50]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I/E9:
httpConnection.setRequestProperty("User-Agent","NetFox"); 7^L
).~ "
Kk3+ ]W<
int responseCode=httpConnection.getResponseCode(); p3s i\Fm!
if(responseCode>=400) V9c.(QY|f
{ <c+.%ka
processErrorCode(responseCode); 1`cH EAa
return -2; //-2 represent access is error 2t= =<x
} s9- qR_
ejN/U{)jK'
9`in r.:
String sHeader; .#[ 9q-
N} EKV
O]N/(pe:d
for(int i=1;;i++) %a%xUce&-X
{ |]\zlH"w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fY<#KM6X
//Utility.log(in.readLine()); AwM`[`ReE
sHeader=httpConnection.getHeaderFieldKey(i); `7"="T~ *
if(sHeader!=null) q lc@$
{ !eX0Q 2
if(sHeader.equals("Content-Length")) CPz<iU
{ ?ZF):}rvZ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ailq,c
break; Qqm?%7A1
} C}huU
} sf*4|P}
else LrU8!r`a
break; !=0h*=NOYt
} L\Se ,
} lY%I("2=
catch(IOException e){e.printStackTrace ();} N>mW64_H)
catch(Exception e){e.printStackTrace ();} .j}]J:{%
(x=$b(I
7KC>?F
Utility.log(nFileLength); RQVu~7d[
3j7FG%\
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return nFileLength; '|8dt "C
} <jh4P!\&j
: auR0FE
*`>BOl+ro
//保存下载信息（文件指针位置） k^5Lv#Z
private void write_nPos() J1w;m/oV
{ /\mtCa.O
try{ jJ$\WUQ.
output = new DataOutputStream(new FileOutputStream(tmpFile)); QiK>]xJ'
output.writeInt(nStartPos.length); qTsy'y;Z
for(int i=0;i<nStartPos.length;i++) f$I=oN
{ { I#>6
// output.writeLong(nPos); 65EMB%
output.writeLong(fileSplitterFetch.nStartPos); 0 QTI;3
output.writeLong(fileSplitterFetch.nEndPos); O(^h_
} rT2Njy1
output.close(); xo>0j#
} JP#S/kJ%3
catch(IOException e){e.printStackTrace ();} ,54z9F`
catch(Exception e){e.printStackTrace ();} EU[\D;
} Gwd38
.}IW!$ dq
O}M-6!%<,
//读取保存的下载信息（文件指针位置） +,e#uuj$p
private void read_nPos() Xa[k=qFo
{ =j.TDv'^nd
try{ t3<MoDe7`r
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3$?6rMl@y
int nCount = input.readInt(); cBxGGggB
nStartPos = new long[nCount]; O<S.fr,
nEndPos = new long[nCount]; #&Hi0..y
for(int i=0;i<nStartPos.length;i++) IuwE&#
{ !"^Zr]Qt+\
nStartPos = input.readLong(); vJWBr:`L
nEndPos = input.readLong(); s9Hxiw@D
} y:'Ns$+
input.close(); 1wFu3fh@
} "i0>>@NR'
catch(IOException e){e.printStackTrace ();} CsZ~LQ=DB
catch(Exception e){e.printStackTrace ();} s6H.Q$3L
} y4-kuMYR
B;k'J:-"
Q'OtXs 80
private void processErrorCode(int nErrorCode) QjTSbHtH
{ /U;j-m&
System.err.println("Error Code : " + nErrorCode); ]az(w&vqg2
} IkCuw./
"6B@V=d
%8*:VR
//停止文件下载 PaCCUF
public void siteStop() BA@E
{ /VYT](
bStop = true; "&6vFmr
for(int i=0;i<nStartPos.length;i++) ^/C\:hw
fileSplitterFetch.splitterStop(); eF+F"|1h
'f( CN3.!
q5;dQ8Y?
} eHr0],
} b A+_/1C
//负责部分文件的抓取 $Q*R/MY
**FileSplitterFetch.java 7zu\tCWb
*/ ]8A*uyi
package NetFox; `~XksyT
}e\"VhAl/
2!#g\"
import java.io.*; o/Ismg-p
import java.net.*; 'z|Da&d P
UoxlEec
g5y+F]'I
public class FileSplitterFetch extends Thread { Z^kE]Ir#EV
M@[W"f Wq
6KddHyFz
String sURL; //File URL Ci`o;KVj
long nStartPos; //File Snippet Start Position f@i#Znkf*?
long nEndPos; //File Snippet End Position n0KpKH<&
int nThreadID; //Thread's ID ,L& yKS@
boolean bDownOver = false; //Downing is over KA2>[x2
boolean bStop = false; //Stop identical eoiz]L
FileAccessI fileAccessI = null; //File Access interface 5,Fq:j)MxW
aC1z.?!U
(L(7)WbH
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException OxHcoNrz
{ -06G.;W\^
this.sURL = sURL; Bsa;,
this.nStartPos = nStart; NBk0P*SI
this.nEndPos = nEnd; ~4fE`-O
nThreadID = id; [Hh*lKg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 iT'doF
} bdL= ?KS
VhO+nvd*W
^yW['H6V
public void run() S~/2Bw!2
{ :E9pdx+
while(nStartPos < nEndPos && !bStop) /EjXyrn2
{ )Rn\6ka
gX"-3w
\c2x udU
try{ #D9.A7fCc5
URL url = new URL(sURL); \,13mB6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '8 .JnCg
httpConnection.setRequestProperty("User-Agent","NetFox"); 2Mx\D
String sProperty = "bytes="+nStartPos+"-"; k[f2`o=
httpConnection.setRequestProperty("RANGE",sProperty); f&<+45JI
Utility.log(sProperty); R+HX'W
]'5Xjcx
KElEGW
InputStream input = httpConnection.getInputStream(); L-9fo-
//logResponseHead(httpConnection); CcQc!`YC
ny KfM5s_
Z@s[8wrmPl
byte[] b = new byte[1024]; w"{DLN[Qw
int nRead; Va )W[I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %`i*SF(gV
{ 8\s#law
nStartPos += fileAccessI.write(b,0,nRead); p7QZn.,=u
//if(nThreadID == 1) /?;'y,(Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fXMY.X>f
} |OeWM
Gazva/e
v>keZZOs
Utility.log("Thread " + nThreadID + " is over!"); yksnsHs}d
bDownOver = true; NgTB4I8P
//nPos = fileAccessI.write (b,0,nRead); +,,(8=5g
} /4T6Z[=s
catch(Exception e){e.printStackTrace ();} @T^FOTW
} xX-r<:'tmi
} Krae^z9R
Ao\P|K9MyL
%,WH*")
//打印回应的头信息 GL?b!4xx
public void logResponseHead(HttpURLConnection con) @)d_zWE
{ LK DfV
for(int i=1;;i++) .2&L.
{ p3vf7eqn
String header=con.getHeaderFieldKey(i); W5Jw^,iPd
if(header!=null) #1-WiweO
//responseHeaders.put(header,httpConnection.getHeaderField(header)); K 4GuOl
Utility.log(header+" : "+con.getHeaderField(header)); o8X_uKEI
else _0+X32HjJ
break; GST#b6S
} @_kF&~
} x3i}IC
lpXGsKH2
hJ(vDv%
public void splitterStop() Z[Tou
{ u\Cf@}5(
bStop = true; j&X&&=
} ^=eC1bQA
u)<]Pb})r
D% jGK
} G4'Ia$
pa46,q&M
x`g,>>&C
/* $z[S0Cm
**FileAccess.java +(2$YJ35
*//文件访问(定位，写) 'i%r
package NetFox; J$}]p
import java.io.*; m\qeYI6,Z
Gko"iO#
l:'#pZ4T
public class FileAccessI implements Serializable{ 0!,uo\`
=.z;:0]'n
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Wxj_DTi[1"
RandomAccessFile oSavedFile; bL xZ5C7t
long nPos; %M`48TW)
"}v.>L<P
5QiQDQT}5
public FileAccessI() throws IOException !'H$08Ql}
{ hdDT'+
this("",0); '4uu@?!dVk
} i2Wvu3,D3-
c*rH^Nz
@Fc:9a@
public FileAccessI(String sName,long nPos) throws IOException US$$ADq
{ @dv8 F "v
oSavedFile = new RandomAccessFile(sName,"rw"); ?JZ$M
this.nPos = nPos; >eA@s}_8
oSavedFile.seek(nPos); Wh i#Ii~
} %[|^7
&:l-;7d
`rVru= zoy
public synchronized int write(byte[] b,int nStart,int nLen) d/R!x{$-f
{ E[t0b5h
int n = -1; s$Vv
try{ }. &ellNQ
oSavedFile.write(b,nStart,nLen); U${W3Ra
n = nLen; hnFpC1TO
} {A/^;X{N^
catch(IOException e) 8;?4rrS
{ e ymv/
e.printStackTrace (); p XXf5adl<
} zx%WV@O9
V<UChD)N`
J'Pyn
return n; vS\2zwb}
} yD~,+}0)
$6Q^ur:
mcQL>7ts
} VaD+:b4
XSC=qg$
qS\#MMsTd
/* kL1<H%1'
**SiteInfoBean.java ?5EH/yV;
*/ =|-=4.b+|
package NetFox; l^&#9d
B,\VLX
t}eyfflZ
public class SiteInfoBean { %]Z4b;W[Y
K ~mUO
aG]>{(~cL
private String sSiteURL; //Site's URL pA*C|g
private String sFilePath; //Saved File's Path ]P3m=/w
private String sFileName; //Saved File's Name 12lX-~[["
private int nSplitter; //Count of Splited Downloading File l$/pp
$ztsbV}
v\,N"X(,
public SiteInfoBean() E<\$3G-do
{//nSplitter的缺省值为5 bqED5;d'#
//default value of nSplitter is 5 nx'c=gp
this("","","",5); O=3/qs6m
} \I!mzo
0cycnOd
m}'_Poc
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) XX/gS=NE#.
{ \Sd8PGl*'
sSiteURL= sURL; H<Sf0>OA
sFilePath = sPath; (1'DZxJ&u
sFileName = sName; i"G'#n~e
this.nSplitter = nSpiltter; gNEcE9y2
{K.H09Y
F(hPF6Zx(
} R `tJ7MB
3Cj)upc
>IIq_6Z#
public String getSSiteURL() To*+Z3Wd
{ S[K5ofV
return sSiteURL; p{L;)WTI
} 1*8;)#%&
cp@Fj"
$/M-@3wro
public void setSSiteURL(String value) j+h+Y|4J
{ hty'L61\z
sSiteURL = value; fLe~X!#HF
} ZoXz@/T
z&gmaYwq
(S!UnBb&
public String getSFilePath() `2 <:$]
{ itzUq,T
return sFilePath; FC1rwXL(
} jUm-!SK}q
.rK0C)
geR :FO;\
public void setSFilePath(String value) yq-~5ui
{ E /H%q|q
sFilePath = value; %NQ%6B
} ,LA'^I?
<uuumi-!%G
NwF"Zh5eMW
public String getSFileName() Be|! S_Y P
{ 6RbDc*
return sFileName; Qbv@}[f
} =c@hE'{
4fKvB@O@.
9;L4\
public void setSFileName(String value) ;3/}"yG<p
{ ^i8,9T'=
sFileName = value; q8$t4_pF
} NAD^10
1)= H2n4)
y8$3kXh
public int getNSplitter() |1%%c %
{ t+KW=eW
return nSplitter; %!\=$s}g
} 5b:1+5iF-
?V2P]|
9&* 7+!
public void setNSplitter(int nCount) L"'=[O~
{ -4x! #|]
nSplitter = nCount; &`qYe)1Eo
} TAUl{??,
} 4+hNP'e
aA4RC0'
iAH,f5T
/* [k$GUU,jY
**Utility.java lWc[Q1
*/ ~Fb@E0 }!
package NetFox; |X=p`iz1&
rpiuFst
QKP #wR
public class Utility { =wX;OK|U(^
9CS"s_
1e[?}q]*
public Utility() t#.}0Te7
{ \r IOnZ.WK
Hpix:To
+1wEoU.l2
} n=-vOa%
(LK@w9)i;
//线程睡眠 !U?C_
public static void sleep(int nSecond) Y)k"KRW+
{ !ldEy#"X
try{ QqF<HCO
Thread.sleep(nSecond); V30w`\1A
} igQzL*X
catch(Exception e) j(y<oxh
{ #MYoy7=
e.printStackTrace (); i]<@
} GgEg(AT
} z/91v#}.
yr+QV:oVA
//日志 zmQQ/7K
public static void log(String sMsg) 8(n>99VVK
{ 'ij+MU1
System.err.println(sMsg); ,IhQ%)l
} cy@oAoBq
)$p36dWl
#fF5O2E'3
public static void log(int sMsg) ?xwi2<zz
{ y"H5>
System.err.println(sMsg); .*N,x(V
} }uMu8)Q
} =EVB?k ,
OF*E1BM
o%Q9]=%!
/* R7IFlQH%
**TestMethod.java s[7$%|~W
*/ h*^JFZb
package NetFox; b6S"&hs
ozsd6&z5l
iJh{,0))g
public class TestMethod { `}t5`:#k
"zw{m+7f,
]iTP5~8U
public TestMethod() O)^F z:
{ ///xx/weblogic60b2_win.exe kR1 12J9P
try{ ]foS.D,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,sj(g/hg
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); c k[uvH
SiteFileFetch fileFetch = new SiteFileFetch(bean); `%|3c
fileFetch.start(); 1?)h-aN
} .K^gh$z!
catch(Exception e){e.printStackTrace ();} q>%.zc[x
rui 8x4c
'\QJ{/JV
} :JBtqpo2
j7);N
[|$C2Dhw=
public static void main(String[] args) GF@`~im
{ ug}u>vQ>
new TestMethod(); IHW s<U
} sz%]rN6$
} 4NRj>y
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