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)); !s$fqn 6
} zv41Yv!x}
for(int i=0;i<nEndPos.length-1;i++) o9/P/PZ\X
{ &m`
nEndPos = nStartPos[i+1]; =GF+hM/~
} j[9B,C4
nEndPos[nEndPos.length-1] = nFileLength; 99 ["I:
} ;$Y?j8g
} 7?Fl [FW$
QO8/?^d
[7bY(
//启动子线程 +=R:n^r^,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?NL2|8
for(int i=0;i<nStartPos.length;i++) ~'ovJ46tx
{ XP'KgTF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Xe5J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6?6 u
nStartPos,nEndPos,i); z"<PveVo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |^ qW
fileSplitterFetch.start(); t5&$ y`
} 1g;3MSn~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n}l Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); HBt?cA '
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &5B+8>
nEndPos = " + nFileLength); "783F:mPh
// fileSplitterFetch[nPos.length-1].start(); C oaqi`v4T
]C!u~A\jq
*q^'%'
//等待子线程结束 !MbRI
//int count = 0; G 5)?!
//是否结束while循环 _?{2{^v
boolean breakWhile = false; 6c2fqAF>i
F?UL0Q|uv
BjA|H
while(!bStop) !%Ak15o
{ RKe19l_V
write_nPos(); E(TY%wO
Utility.sleep(500); b`^$2RM&
breakWhile = true; +G?3j,a\
(k[<>$hL*
eN/Jb;W
for(int i=0;i<nStartPos.length;i++) @-hy:th#
{ h.67]U7m
if(!fileSplitterFetch.bDownOver) 4EOu)#
{ X3nwA#If1
breakWhile = false; U<*dDE~z
break; 2-$R@ SVy
} 0Vg8o @
} 2W}RXqV<
if(breakWhile) z.QW*rW9
break; Cnn,$R=/s
IRpCbTIXK
O".#B
//count++; ZI8p(e
//if(count>4) ~sM334sQ
// siteStop(); zNBG;\W
} &B))3WFy
=14pEe
=~R0U
System.err.println("文件下载结束！"); Ar|_UV>Zf
} Wjj'yqBO^
catch(Exception e){e.printStackTrace ();} y_\d[
} *QrTZ$\C
[P 8e=;
a+]@$8+
//获得文件长度 2^|*M@3r
public long getFileSize() j3$KYf`T}
{ F.JE$)B2EX
int nFileLength = -1; P/^:IfuR
try{ 5Eq_L
URL url = new URL(siteInfoBean.getSSiteURL()); \wTWhr0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HSTtDTo
httpConnection.setRequestProperty("User-Agent","NetFox"); GLEGyT?~
zhFGMF1
%R}}1
int responseCode=httpConnection.getResponseCode(); Rrsz{a
if(responseCode>=400) v=|ahsYC
{ rl!c\
processErrorCode(responseCode); `DEz ` D
return -2; //-2 represent access is error 6}[W%S]8
} gPDc6{/C<
yXlzImPn
'GAjx{gM
String sHeader; ,KZ_#9[>
X.g1 312~
:c c#e&BO
for(int i=1;;i++) <x,$ODso
{ {"O'kx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [7$.)}Q-
//Utility.log(in.readLine()); '#^ONnSTn
sHeader=httpConnection.getHeaderFieldKey(i); ~]}7|VN.}
if(sHeader!=null) ny{|{a
{ qRTy}FU1
if(sHeader.equals("Content-Length")) uZi]$/ic
{ )bqO}_B
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Dk/;`sXV
break; 7v#sr<
} BsRxD9r
} I:[3x2H
else {G_ZEo#x8,
break; ) _"`{2
} fAYm3+.l3
} XD9lox
catch(IOException e){e.printStackTrace ();} u PjJ>v
catch(Exception e){e.printStackTrace ();} l,L#y4#
cu.f]'
9FK%"s`
Utility.log(nFileLength); $5:j" )$,
waldLb>7D
qY0p)`3!%
return nFileLength; ?PLf+S
} Hcuvu[)T"
`}"*i_0-5'
;ZB[g78%R%
//保存下载信息（文件指针位置） Q R;Xj3]v
private void write_nPos() "Qm
{ e5C560
try{ `9%@{Ryo
output = new DataOutputStream(new FileOutputStream(tmpFile)); v-EcJj%
output.writeInt(nStartPos.length); 1%t9ic
for(int i=0;i<nStartPos.length;i++) Y@F@k(lOo
{ mZ'`XAS~;
// output.writeLong(nPos); cV=h8F
output.writeLong(fileSplitterFetch.nStartPos); (m25ZhW
output.writeLong(fileSplitterFetch.nEndPos); Z_Hc":4i
} YrFB~z.V
output.close(); *e!0ZB3J
} ^ola5wD
catch(IOException e){e.printStackTrace ();} P;{f+I|`
catch(Exception e){e.printStackTrace ();} )mS Aog<
} *ax$R6a#X
V~%!-7?
_|`S9Nms
//读取保存的下载信息（文件指针位置） ,)|nxX
private void read_nPos() V'^Hn?1^
{ D!+d]A[r
try{ .sgP3Ah
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ymiOtA Z
int nCount = input.readInt(); ESft:3xyw
nStartPos = new long[nCount]; ]:8:|*w
nEndPos = new long[nCount]; Wyd,7]'z)Z
for(int i=0;i<nStartPos.length;i++) cE$7CSR
{ ??Q'| r
nStartPos = input.readLong(); tY~EB.%
nEndPos = input.readLong(); { owK~
} fKb8)PDP
input.close(); S2'./!3yv
} Qk*`9
catch(IOException e){e.printStackTrace ();} [}}?a
catch(Exception e){e.printStackTrace ();} xp.~i*!`
} 3{O^q/R
' cR||VX
+:+q,0~*]
private void processErrorCode(int nErrorCode) |9Q4VY'";
{ }vgeQh-G
System.err.println("Error Code : " + nErrorCode); Z.ky=vCt
} TFjb1a,)
IC"bg<L,*
Ko|nF-r_
//停止文件下载 8GgZAu'X
public void siteStop() a6cq0g[#z
{ 2x<,R/}
bStop = true; ;shhgz$
for(int i=0;i<nStartPos.length;i++) Bf1,(^3XH
fileSplitterFetch.splitterStop(); %\IB_M
4}E|CD/pZ
%F_)!M;x
} F<39eDNpz
} -|YG**i/
//负责部分文件的抓取 D,b'1=
**FileSplitterFetch.java 3copJS
*/ dZK/v
package NetFox; ;89 `!V O
T)?:q
:[YHJaK
import java.io.*; LX2rg\a+%
import java.net.*; [|.IXdJ!
=bgzl=A`
0A9llE
public class FileSplitterFetch extends Thread { K[r<-6TS
"H\1Z,P<m
%/iD@2r
String sURL; //File URL 5+Fr/C
long nStartPos; //File Snippet Start Position H3CG'?{ _
long nEndPos; //File Snippet End Position @)k/t>r(
int nThreadID; //Thread's ID |mvY=t %
boolean bDownOver = false; //Downing is over @K.{o'
boolean bStop = false; //Stop identical EIQ`?8KSR
FileAccessI fileAccessI = null; //File Access interface ^,O%E;g^#
+?y ', Ir
= Lt)15
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException blyU53g
{ 0P i+ (X
this.sURL = sURL; i;B &~
this.nStartPos = nStart; pDqX% $^
this.nEndPos = nEnd; !1(*D*31
nThreadID = id; L8R{W0Zr>!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 n<q1itjD
} d^h`gu~3
4~<78r5m
c@f?0|66M
public void run() %n?&#_G|
{ fSc)PqLP
while(nStartPos < nEndPos && !bStop) t@r>GHO
{ ETZE.a
ISa}Km>Q
+guCTGD:
try{ 3ScOJo
URL url = new URL(sURL); ^IW5c>;|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r)<c ~\0 7
httpConnection.setRequestProperty("User-Agent","NetFox"); gOb"-;Zw
String sProperty = "bytes="+nStartPos+"-"; M]|tXo$?
httpConnection.setRequestProperty("RANGE",sProperty); PzF>yG[
Utility.log(sProperty); jEhPx
CZZwBt$P
1?I_fA}
InputStream input = httpConnection.getInputStream(); YF8;s4
//logResponseHead(httpConnection); R|D%1@i]
*{y({J
(:er~Y}
byte[] b = new byte[1024]; lC.Q61J@
int nRead; N$ oQK(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) BN7]u5\7
{ Mbm'cM&}
nStartPos += fileAccessI.write(b,0,nRead); !#&`1cYX
//if(nThreadID == 1) xu%_Zt2/?j
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Dxvizd>VU
} 1FA:"0lO
(}B3df
E)>.2{]C>
Utility.log("Thread " + nThreadID + " is over!"); >G9YYt~
bDownOver = true; *RYok{w
//nPos = fileAccessI.write (b,0,nRead); ^O6eFD U
} G]v BI=
catch(Exception e){e.printStackTrace ();} 6+UTEw;
} LO;7NK
} (jmF7XfU
>;Ag7Ex
\^oI3K0`
//打印回应的头信息 <#nt?Xn
public void logResponseHead(HttpURLConnection con) s,CN<`/>x
{ x`:c0y9uG
for(int i=1;;i++) PQj'D<G
{ XgI;2Be+&a
String header=con.getHeaderFieldKey(i); o'EJ,8
if(header!=null) *q&^tn b
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;{lb_du2:
Utility.log(header+" : "+con.getHeaderField(header)); E]O/'-
else L}=DC =E
break; :X*$U ~aQ
} S:lie*Aux*
} eC{St0
8AVtUU
?ESsma6
public void splitterStop() 3d`u!i?/
{ 4^Ke?;v
bStop = true; C;3
} mWUkkR(/
-{XDQ{z<%
ZS<`.L6B3
} nV:RL|p2jw
"l 8YD&q
XvSng"f.
/* icK$W2<8mg
**FileAccess.java =4[ U<opP
*//文件访问(定位，写) Hk f<.U
package NetFox; 3ytlD'
import java.io.*; :i3 W U%
=odKi"-6
yGY:EvH^?
public class FileAccessI implements Serializable{ V]Rt[l]
|b4f3n
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Skg}/Ek
RandomAccessFile oSavedFile; +!Q*ie+q
long nPos; S3UJ)@ E
u!-v1O^[
4L bll%[9
public FileAccessI() throws IOException XL7||9,(h
{ '=0l{hv@
this("",0); TKp2C5bX
} '':MhRb
x7xMSy
.uinv
public FileAccessI(String sName,long nPos) throws IOException !]3kFWs
{ MTip4L W9
oSavedFile = new RandomAccessFile(sName,"rw"); cT5BBR
this.nPos = nPos; p\P)
oSavedFile.seek(nPos); =w!2R QB
} Wl7S<>hg4
Q?V+ 0J
*/HW]x|?V~
public synchronized int write(byte[] b,int nStart,int nLen) |~o0-: 'C
{ I!#WXK
int n = -1; v|MT^.
try{ Cg(&WJw(ep
oSavedFile.write(b,nStart,nLen); sd%m{P2
n = nLen; ||L^yI~_d
} &5[B\yv
catch(IOException e) nAC>']K4$
{ ]N2! 'c
e.printStackTrace (); h1H$3TpP
} QHxof7
H$V`,=H
dT0>\9ZNr
return n; j#Qnu0D
} F9"Xu-g
Z~w2m6;s
O!t=,F1j
} IhN^*P:Fo
LzxO=+=9!q
8|(],NyEJ
/* /'/i?9:
**SiteInfoBean.java 4jc?9(y%
*/ vjzG H*
package NetFox; D |=L)\
$<9u:.9xf
AhkDLm+
public class SiteInfoBean { yDJy'Z_F{
Gr>CdB>~+
)FSEHQ
private String sSiteURL; //Site's URL ol K+|nR
private String sFilePath; //Saved File's Path +|x{?%.O
private String sFileName; //Saved File's Name G`;\"9t5h
private int nSplitter; //Count of Splited Downloading File m[z$y
(I`lv=R"j
`v-O 4Pk
public SiteInfoBean() :`4F0
{//nSplitter的缺省值为5 a`8]TD
//default value of nSplitter is 5 &Yo|Pj
this("","","",5); FJ^\K+;
} yh/JHo;
UM`{V5NG#
*$5p,m6G
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /+*N.D'`t,
{ h$}PQ
sSiteURL= sURL; 1]9w9!j
sFilePath = sPath; QJ(5o7Tfn
sFileName = sName; )dFPfu&HL
this.nSplitter = nSpiltter; 3yw$<lm
6#AEVRJKU@
'oK oF
} p/88mMr
8rx|7
5F!Qn\{u{
public String getSSiteURL() `*elzW
{ ak-agH
return sSiteURL; [?hvx}
} [Y~~C J
MN8>I=p
&CcW(-
public void setSSiteURL(String value) ]Y-Y.&b7t
{ |N^"?bSt
sSiteURL = value; _n/73Oh
} C\joDAD
g?xD*3<
4U_+NC>b
public String getSFilePath() :<mJRsDf
{ F+GX{e7E\
return sFilePath; /G|v.#2/g
} yXoNfsv
4lWqQVx
VdGVEDwz
public void setSFilePath(String value) K a& 2>F
{ PO8Z2"WI
sFilePath = value; #0vda'q=j
} ; o Y|~
|d&C<O;f
,vO\n^
public String getSFileName() S0Io$\ha
{ kz1#"8Zd!
return sFileName; /a<UKh:A[
} Kc95yt
7y&6q`y E
nu7 R
public void setSFileName(String value) nGe4IY\-w
{ vy}_aD{B
sFileName = value; 4I$Y"|_e
} ;[UI]?A%
e[?,'Mp9
:V5 Co!/+
public int getNSplitter() BWQ`8
{ SMIDW}U2S
return nSplitter; <F(S_w62
} [qW%H,_
4sntSlz)~k
2$kB^g!:o
public void setNSplitter(int nCount) bhGRD{=
{ _/z_ X
nSplitter = nCount; tkR~(h
} jL8A_'3B
} Z5n-3h!+ED
w|]Tt="
Z$g'h1,zW
/* vanV|O
**Utility.java [5p3:D
*/ l"(PP3
package NetFox; Gp \-AwE
MZ&.{SY7
MH#"dGGu
public class Utility { 1;1;-4k7I
A$N%deb
6IV):S~
public Utility() &Z[+V)6,,
{ Pj]^p{>
(3mL!1\
p<(a);<L
} @'}2xw[eU
]7cciob
//线程睡眠 @IsUY(Gu
public static void sleep(int nSecond) ?4U4o<
{ S*=^I2;
try{ LdH1sHy*d`
Thread.sleep(nSecond); S9P({iZK
} oJ %Nt&q
catch(Exception e) m3Wc};yE*Q
{ W{.:Cf9
e.printStackTrace (); =DfI^$Lr:
} zN!yOlp5
} rP'%f 6
HZ%V>88
//日志 wkGr}
public static void log(String sMsg) Iy49o!
{ %6 Av1cv
System.err.println(sMsg); fMFkA(Of^
} &"JC8
^7/v[J<<
H390<`
public static void log(int sMsg) L=qhb;[L
{ AV2Jl"1)z
System.err.println(sMsg); 5I2 h(Td
} '%t$mf!nV
} %;ED}X
HBR/" m
gEsD7]o(=
/* 8)eRm{
**TestMethod.java U ->vk{v
*/ APF`b
package NetFox; 8v2Wi.4T
P8ej9ULX,
@}H'2V
public class TestMethod { MYvz%7
t2{(ETV
-e(<Jd_=
public TestMethod() -s2)!Iko&
{ ///xx/weblogic60b2_win.exe jd ;)8^7K
try{ Qc-W2%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g2TK(S|#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r3U7`P
SiteFileFetch fileFetch = new SiteFileFetch(bean); Jj[3rt?8
fileFetch.start(); Mn/
} gizY4~ j
catch(Exception e){e.printStackTrace ();} 1}|y^oB\-
yN{**?b
jZqa+nG51
} [dP<A?s
]~dB|WB
,&4 [`d
public static void main(String[] args) 8A]8yX =
{ 0'r}]Mws
new TestMethod(); >S`=~4
} #e-7LmO~
} paD[4L?4Hk
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