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)); Qdn:4yk
} -qEr-[z
for(int i=0;i<nEndPos.length-1;i++) W ,U'hk%
{ nx+& {hn(
nEndPos = nStartPos[i+1]; W1!eY,1}
} 6,h<0j{
nEndPos[nEndPos.length-1] = nFileLength; jF5JpyOc
} y@Or2bO#
} 'q-h kN
tQ|I$5jNJ
Y~:7l5C
//启动子线程 kL3=7t^ 1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nSC>x:jY5/
for(int i=0;i<nStartPos.length;i++) X@G`AD'.M
{ n$?oZ*;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }rQ*!2Y?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), G`P+J
nStartPos,nEndPos,i); ;8v5 qz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ( 0h]<7
fileSplitterFetch.start(); i~9)Hz;!
} Cn<kl^!Q-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |S8pq4eKJ_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C,]Ec2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GGuLxc?(
nEndPos = " + nFileLength); 3TtW2h>M
// fileSplitterFetch[nPos.length-1].start(); aF=VJ+5
:W&\})
{h=Ai[|l4Q
//等待子线程结束 ?7+2i\L
//int count = 0; [~o3S$C&7
//是否结束while循环 -+=8&Wa
boolean breakWhile = false; <>Im$N ai
gn%"dfm
: L>d]Hn
while(!bStop) zW _'sC
{ YH>n{o;- ?
write_nPos(); ;@ e|}Gk
Utility.sleep(500); :+=*
breakWhile = true; 3IkG*enI
!:8!\gE^P
;4bu=<%
for(int i=0;i<nStartPos.length;i++) 8dH|s#.4um
{ N#:"X;
if(!fileSplitterFetch.bDownOver) h CiblM
{ \2`U$3Q
breakWhile = false; u&Fm}/x
break; lrzW H0Q
} 3{l"E(qqZ
} 0{yx*}.
if(breakWhile) iI1t P
break; Ame%:K!t
_6' g]4
b+hY^$//
//count++; D4|_?O3|m
//if(count>4) WKf~K4BL>
// siteStop(); Q'VS]n
} 8\9EDgT
7,zARWB!?
4Rn i7qH
System.err.println("文件下载结束！"); }NXESZYoi
} vn<S"
catch(Exception e){e.printStackTrace ();} cjXwOk1:s
} y ^\8x^Eg
;k8}D*?8
}0( Na
//获得文件长度 cOQy|v`KD,
public long getFileSize() UU;:x"4
{ ht|r+v-
int nFileLength = -1; >`:+d'Jv0
try{ 66*o2D\Q*G
URL url = new URL(siteInfoBean.getSSiteURL()); PwW@I~@>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^XM;D/Gp~
httpConnection.setRequestProperty("User-Agent","NetFox"); ]`prDw'
m C Ge*V}
Q Y'-]
int responseCode=httpConnection.getResponseCode(); I,eyL$x
if(responseCode>=400) 5o/rV.I
{ Jy_'(hG
processErrorCode(responseCode); d eg>m?Y
return -2; //-2 represent access is error g8Z14'Ke
} Eg*3**gTO
^U}0D^jDeE
o[#a}5Y
String sHeader; z"3c+?2
(zBQ^97]
Z3dd9m#.]
for(int i=1;;i++) oK6lCGM5
{ tOw 0(-:iq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S2)S/ nf
//Utility.log(in.readLine()); _LNPB$P
sHeader=httpConnection.getHeaderFieldKey(i); 7;NV 1RV
if(sHeader!=null) ^&iV%vQ[
{ dK: "
if(sHeader.equals("Content-Length")) e`r;`a&
{ {P&^Erx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o2
break; 37xxVbik
} kg@h R}
} F6p1 VFs
else {%{GZ
break; Ao T7sy7
} L])w-
} jhv1 D'>6
catch(IOException e){e.printStackTrace ();} cqx1NWlY
catch(Exception e){e.printStackTrace ();} \]xYV}(FO
h>:RCpC
"zbE
Utility.log(nFileLength); 5H+k_U
k5D'RD
;L2bC3
return nFileLength; \aIy68rH,
} %%6('wi
c'";36y
)/"7$2Aoy
//保存下载信息（文件指针位置） &F_rg,q&_
private void write_nPos() 31& .Lnq
{ u9w&q^0dqG
try{ c^s>
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,rQ)TT
output.writeInt(nStartPos.length); 'qAfei']
for(int i=0;i<nStartPos.length;i++) r%d11[z
{ a}fClI-u
// output.writeLong(nPos); p^P y,
output.writeLong(fileSplitterFetch.nStartPos); OPW"ABJ
output.writeLong(fileSplitterFetch.nEndPos); ,<b|@1\k
} /T[ICd2J
output.close(); CDj Dhs
} e"#D){k#
catch(IOException e){e.printStackTrace ();} &pjV4m|j<
catch(Exception e){e.printStackTrace ();} ~aAJn IO
} Y,btL'[W
!"%sp6Wc
mthl?,I|
//读取保存的下载信息（文件指针位置） o'/C$E4W
private void read_nPos() 3^>a TU<Z
{ od*Z$Hb>'
try{ vN:[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uz3pc;0LPY
int nCount = input.readInt(); xY2_*#{.
nStartPos = new long[nCount]; *)1Vs'!-
nEndPos = new long[nCount]; Wxau]uix
for(int i=0;i<nStartPos.length;i++) [P=[hj;
{ g)qnjeSs]
nStartPos = input.readLong(); ^85n9a?8
nEndPos = input.readLong(); 8zDH<Gb
} ApYud?0b
input.close(); x ;,xd
} d`uO7jlm
catch(IOException e){e.printStackTrace ();} v9m;vWp
catch(Exception e){e.printStackTrace ();} Tw;qY
} WwtE=od
D"4&9"CU
V9u\;5oL
private void processErrorCode(int nErrorCode) 86fK=G:>
{ NjN?RB/5
System.err.println("Error Code : " + nErrorCode); -MU.Hu
} nDB 2>J
cO+Xzd;838
"%''k~UD4
//停止文件下载 D%UZ'bHN*
public void siteStop() e ]o'i;I
{ =yX&p:-&
bStop = true; r>~d[,^$m4
for(int i=0;i<nStartPos.length;i++) V!77YFen %
fileSplitterFetch.splitterStop(); Y%:0|utQC
5b1uD>,;y
rjHIQC C
} uk[< 6oxz
} 8+ F}`lLA
//负责部分文件的抓取 D`:d'ow~KQ
**FileSplitterFetch.java uO@3vY',n
*/ D&l,SD
package NetFox; Secq^#]8
xVkTRCh
{XD/8m(hN|
import java.io.*; 2FIR]@MQd
import java.net.*; E<Dh_K
bLEATT[
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public class FileSplitterFetch extends Thread { n<<=sj$\!
)w2K&Zr0
J4v0O="
String sURL; //File URL gZlw
long nStartPos; //File Snippet Start Position \DU^idp#
long nEndPos; //File Snippet End Position xDGS`U
int nThreadID; //Thread's ID guOSO@
boolean bDownOver = false; //Downing is over PN"8 Y
boolean bStop = false; //Stop identical .6ngo0<g
FileAccessI fileAccessI = null; //File Access interface QhXC>)PW
a=*ALd_&0
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;=-j;x
{ 6L,lq;
this.sURL = sURL; R'I_xjC
this.nStartPos = nStart; a WeBav}_
this.nEndPos = nEnd; >*= =wlOB
nThreadID = id; q)V1{B@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %U5P}
} O5qW*r'
%x}&=zx0*1
Y62u%':X
public void run() wY3|#P CDV
{ b-BM"~N'
while(nStartPos < nEndPos && !bStop) o)#q9Vk%b
{ Seq]NkgY
~llMrl7
~|'y+h89
try{ w3<"g&n|
URL url = new URL(sURL); :'y{dbKp"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x*h`VS(?6
httpConnection.setRequestProperty("User-Agent","NetFox"); d]CviQUq
String sProperty = "bytes="+nStartPos+"-"; 97Zk P=Cq
httpConnection.setRequestProperty("RANGE",sProperty); p:JRQT"A
Utility.log(sProperty); hD6JW-
L$lo~7<]
tS (i711
InputStream input = httpConnection.getInputStream(); 6h2x~@
//logResponseHead(httpConnection); t{Hh&HX
9^PRX
22GnbA7O
byte[] b = new byte[1024]; =! N _^cb
int nRead; <AMb!?Obh
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E7gHi$
{ -@SOo"P
nStartPos += fileAccessI.write(b,0,nRead); <TR/ `
//if(nThreadID == 1) my ;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ik2- OM
} +ze}0lrEL
CF|moc:;
m<4s*q0\i
Utility.log("Thread " + nThreadID + " is over!"); V$dJmKg
bDownOver = true; G@!_ZM8h
//nPos = fileAccessI.write (b,0,nRead); g\o{}Q%X
} .-SF$U_P*a
catch(Exception e){e.printStackTrace ();} N7*CP|?E
} ]*2EK9<
} L\b]k,Ksf
_%wK}eH+sy
-G],H)M
//打印回应的头信息 gX@nPZjg
public void logResponseHead(HttpURLConnection con) (0E U3w?]
{ Vk-W8[W 7
for(int i=1;;i++) ~reQV6oQua
{ .3{[_iTM
String header=con.getHeaderFieldKey(i); 2{t)DUs
if(header!=null) {)B9Z I{+A
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'e.q 7Jpd
Utility.log(header+" : "+con.getHeaderField(header)); w"cM<Ewu
else 4%wq:y< )/
break; $D QD$
} f?%qUD_#
} `'p`PyMt`
rI0)F
rIeM+h7Wn
public void splitterStop() :E>&s9Yj?
{ ybZ}
bStop = true; ]alh_U
} [_WI8~gY
g4N%PV8
jHAWK9fa
} /M3y)K`^
ku{XW8
cz2,",+~
/* \Okc5;kB2
**FileAccess.java S dIGU[fm
*//文件访问(定位，写) /Q?~Q0{)es
package NetFox; dgS4w@)@V;
import java.io.*; )xB$LJM8
dh&W;zs
TdQ]G2
public class FileAccessI implements Serializable{ :T_'n,
|d $1wr
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =G(*gx
RandomAccessFile oSavedFile; 6nh]*/
long nPos; X[V?T>jsM
yeh8z:5Z O
RcgRaQ2^
public FileAccessI() throws IOException !\CG,Ek
{ CN7k?JO<
this("",0); Q0pzW:=s]
} hUVk54~l
i{8]'fM
16I&7=S,
public FileAccessI(String sName,long nPos) throws IOException H(G!t`K
{ %a5t15 9
oSavedFile = new RandomAccessFile(sName,"rw"); 7p^@;@V
this.nPos = nPos; ~<n(y-P^
oSavedFile.seek(nPos); >;)2NrJV
} h$70H^r
9b1?W?"
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public synchronized int write(byte[] b,int nStart,int nLen) SD?BM-&~
{ A2y6UzLYD
int n = -1; 2B-.}OJ
try{ m}98bw
oSavedFile.write(b,nStart,nLen); rFo\+//
n = nLen; }sv!=^}BY3
} h40'@u^W
catch(IOException e) a mqOxb
{ "OO96F
e.printStackTrace (); U^[<
} %y>+1hakkX
=_[2n?9y
u?F (1iN=
return n; =p]mX)I_
} Y]N~vD
+0J@y1
|xh&p(
} Z==!C=SBv
GM](=|F
s`"OM^[-
/* f')c/Yw
**SiteInfoBean.java jyiFM5&
*/ 1HhX/fpq
package NetFox; ]ni6p&b>
)\wuesAO
abBO93f^
public class SiteInfoBean { #$FrFU;ZR
_#!U"hkH
7R,qDp S
private String sSiteURL; //Site's URL OUzR@$
private String sFilePath; //Saved File's Path i^*M^P3m
private String sFileName; //Saved File's Name thuRNYv<
private int nSplitter; //Count of Splited Downloading File S ZlC4=6c
1Dq<{;rWb
bhD ~4Rz
public SiteInfoBean() Ry z?v<)h
{//nSplitter的缺省值为5 +3;Ody"59
//default value of nSplitter is 5 %ISq>A)%
this("","","",5); }B0sC%cm
} rfs(#
GP+2/D
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) HY;9?KJ'
{ .k@^KY
sSiteURL= sURL; gfde#T)S
sFilePath = sPath; ?`"n3!>bS
sFileName = sName; 8Atq,GcG
this.nSplitter = nSpiltter; H<`\bej,
;3;2h+U*
;L~p|sF
} }3Y <$YL"R
_A{+H^,
ZQAO"huk]
public String getSSiteURL() :"<e0wDu[
{ @'i+ff\
return sSiteURL; ;F5"}x
} R)oB!$k
%<}<'V0
fW(/Loh
public void setSSiteURL(String value) @vRwzc\
{ ]78!!G[`
sSiteURL = value; pYo=oI
} W;zpt|kAH
XA<ozq'
XJgh>^R^
public String getSFilePath() h?Nek+1'
{ >{5 p0
return sFilePath; \\:|Odd
} &nY;=Hv`WY
r\2vl8X~
5Fbs WW2
public void setSFilePath(String value) 2q PhLCeZ
{ :et#0!
sFilePath = value; 2-dh;[4
} 3K>gz:dt
kz B\'m,l
khx.yRx
public String getSFileName() raE Mm
{ 19c@`?
return sFileName; 2&he($HIzg
} ^m!_2_q
sw;|'N$:<
:,S98z#
public void setSFileName(String value) z.oU4c
{ .[:VSM7T
sFileName = value; 8{0k0 &x
} :Q_3hK
%S@L|t
M`7y>Ud
public int getNSplitter() F~HRME;Z
{ 5o)Y$>T0
return nSplitter; 8Pmdk1 ~
} 0;<)\Wt=i9
!GwL,)0@^
-Z0+oU(?YE
public void setNSplitter(int nCount) J !HjeZ
{ g(Yb^'X/
nSplitter = nCount; *?t%0){
} A"uULfnk
} 65TfFcQ<S
&GhPvrxI?
CnISe^h
/* uw AwWgl
**Utility.java G[,Q95`w?<
*/ wN=;i#
package NetFox; S($Su7g%_
0 1V^L}
iW%8/$
public class Utility { R=]d%L8
xQ4%e[/
u92^(|
public Utility() xSMt*]=9
{ N&,]^>^u
fv!?Ga(
-/P\"c
} pH@]Y+W
SaOYu &>
//线程睡眠 \%0n}.A
public static void sleep(int nSecond) Gl}Qxv#$
{ j%IF2p2
try{ Oy57$
Thread.sleep(nSecond); CGbwmPx
} @FO)0
catch(Exception e) wkUlrL/~
{ LR(-<"
e.printStackTrace (); 4_/?:$KO
} 5PT5#[
} MGJ.,tK1
k8AW6oO/i
//日志 n'1'!J;Q
public static void log(String sMsg) yQNV@T<o
{ P"/G
System.err.println(sMsg); IZ/m4~
} k,yZ[n|`
5=|hC3h
j|4C\~i
public static void log(int sMsg) )wvHGecp*
{ Ho;X4lo[j
System.err.println(sMsg); yQ,{p@#X8
} V[o`\|<
} ,Wbwg
*)M49a*UD
Gh.[dF?
/* 6( CDNMzj
**TestMethod.java 6!'3oN{
*/ BZ!v%4^9
package NetFox; ;!!n{l$r'
&-d&t` `
9H-|FNz?c
public class TestMethod { %a+mk E
G+UMBn
\R36w^c3
public TestMethod() #X 52/8G
{ ///xx/weblogic60b2_win.exe j)C,%Ol
try{ H,nec<Jp
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o%9*B%HO/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {(U %i\F\
SiteFileFetch fileFetch = new SiteFileFetch(bean); {!t7[Ctb
fileFetch.start(); eq(am%3~
} fk1ASV<rN
catch(Exception e){e.printStackTrace ();} }X*Riu7gk
li~d?>
I M-L'9
} (3J$>Na
Szbb_i{_ `
}J">}j]/
public static void main(String[] args) tg]x0#@s
{ 26&'X+n&
new TestMethod(); &0 >Loja`^
} R}^~^#
} ks$JP6
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