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)); SQB[d3f
} )FrXD3p
for(int i=0;i<nEndPos.length-1;i++) P7GF"/
{ /P/S0
nEndPos = nStartPos[i+1]; Ug^v ]B9
} "xV9$m>
nEndPos[nEndPos.length-1] = nFileLength; &N!;d E
} [!E8C9Q#!
} LMvsYc~]q
+wwK#ocw
`cgSyRD]
//启动子线程 Ag`:!*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }~RH!Q1
for(int i=0;i<nStartPos.length;i++) {6yiD
{ Lc<C1I 5=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W|FPj^*t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L@{5:#-
nStartPos,nEndPos,i); g2<xr;<t^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qeyBZ8BG
fileSplitterFetch.start(); HEjrat;5
} Wh)QCp0|n
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X>#!s Lt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); QxmVImn"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FFNv'\)
nEndPos = " + nFileLength); |h,aV(Q
// fileSplitterFetch[nPos.length-1].start(); 04wmN
y8KJoVPiM
C9q`x2
//等待子线程结束 !.'@3-w]
//int count = 0; S/ Y1NH
//是否结束while循环 hD>O LoO
boolean breakWhile = false; ^xGdRaU#
;ml;{<jI
)up!W4h6o
while(!bStop) Z=Oo%lM6B
{ 2EOt.4cP
write_nPos(); ;TK:D=p4
Utility.sleep(500); av1*i3
breakWhile = true; dfo{ B/+
;q&>cnLDR
Iky'x[p,D
for(int i=0;i<nStartPos.length;i++) Y24:D7Q
{ >4.{|0%ut
if(!fileSplitterFetch.bDownOver) j!;?=s
{ G!54 e
breakWhile = false; PT|W{RlNl
break; $zTjh~ 9
} dOFxzk,g&R
} wL2d.$?TEg
if(breakWhile) CW Y'q
break; ~mtL\!vaM
=J,aBp
Nd&u*&S
//count++; |/g\N,]
//if(count>4) Zjt3U;Y
// siteStop(); DiAPs_@
} 7:1c5F~M
EY(@R2~#J
9z,?DBMvc
System.err.println("文件下载结束！"); <dzE5]%\
} C,w$)x5kls
catch(Exception e){e.printStackTrace ();} \)ac,i@fy
} ?EeHeN_
n2R{$^JxO
NwmO[pt+
//获得文件长度 gUCv#:
public long getFileSize() ,c6ID|\
{ Gt[!q\^?
int nFileLength = -1; S2"p(
try{ aF$HF;-y
URL url = new URL(siteInfoBean.getSSiteURL()); 3_IuK6K2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }@V(y9K
httpConnection.setRequestProperty("User-Agent","NetFox"); CCX\"-C
}abM:O "Y
:JSOj@s
int responseCode=httpConnection.getResponseCode(); m5sgcxt/
if(responseCode>=400) +GWeu0b(~
{ z@cL<.0CE
processErrorCode(responseCode); &gkloP@
return -2; //-2 represent access is error pd,5.d
} Gu&?Gn oc
fw_V'l#\
`ejE)VL=8h
String sHeader; U]fE(mpI9
pHY~_^B4&
)[6H!y5
for(int i=1;;i++) z48,{H6h
{ j3~:\H
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); LI?rz<H!D
//Utility.log(in.readLine()); o\8yYX
sHeader=httpConnection.getHeaderFieldKey(i); L^)&"6oSa
if(sHeader!=null) 7 #_{UJ%
{ 5-bd1!o
if(sHeader.equals("Content-Length")) QdG_zK>|e
{ ;*+jCL2F
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /+Xv(B
break; ?T70C9
} (hVhzw"~
} u|=_!$8
else `Y/DttjL
break; V$-IRdb
} APuG8 <R,
} B[Uvj~g
catch(IOException e){e.printStackTrace ();} :M1S*"&:
catch(Exception e){e.printStackTrace ();} G6Z2[Ej1
4_`+&
\no[>L]
Utility.log(nFileLength); 'rU [V+
y-{^L`%Mk
]E88zWDY`
return nFileLength; ooByGQ90V:
} )=;0
Ym-uElWo
<r,l
//保存下载信息（文件指针位置） 4W~pAruwr
private void write_nPos() KQ xKU?b1
{ Uw5z]Jck
try{ x\!Qe\lE
output = new DataOutputStream(new FileOutputStream(tmpFile)); )`^t,x<S
output.writeInt(nStartPos.length); d$kGYMT"
for(int i=0;i<nStartPos.length;i++) y_38;8ex
{ "W|Sh#JF
// output.writeLong(nPos); 3IZ^!J
output.writeLong(fileSplitterFetch.nStartPos); 7Rk eV
output.writeLong(fileSplitterFetch.nEndPos); $TL~SVHj;{
} DTt/nmKAqJ
output.close(); #~q{6()e:
} g%#" 5Kr
catch(IOException e){e.printStackTrace ();} FlRbGg^
catch(Exception e){e.printStackTrace ();} ]6p?mBuQ
} kp[+Iun?
rcPP-+XW
NHUx-IqOX
//读取保存的下载信息（文件指针位置） %?y ?rt
private void read_nPos() \q(RqD
{ 'd^U!l
try{ X26gl 'U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %w,
int nCount = input.readInt(); %7Z_Hw
nStartPos = new long[nCount]; y|nMCkuX
nEndPos = new long[nCount]; 9PVM06
for(int i=0;i<nStartPos.length;i++) M$ `b$il
{ 7Nw7a;h
nStartPos = input.readLong(); j{IAZs#@>
nEndPos = input.readLong(); +L!-JrYHS4
} IR?ICXmtx
input.close(); Y>{K2#k
} { o=4(RC
catch(IOException e){e.printStackTrace ();} I`}-*%ki(
catch(Exception e){e.printStackTrace ();} $xyG0Q.
} "6lf~%R"
OA_:_%a(
"?EA G
private void processErrorCode(int nErrorCode) Mje6Q
{ r Ka7[/
System.err.println("Error Code : " + nErrorCode); x1]^].#Eo
} 0"kNn5
C#`eN{%.YT
uR|Jn)/m(
//停止文件下载 ync2X{9D
public void siteStop() zJOjc/\
{ [7ZFxr\:!
bStop = true; 9;k_"@A6
for(int i=0;i<nStartPos.length;i++) l!<Nw8+U
fileSplitterFetch.splitterStop(); Rgw\qOb
H*!j\|v0
=4"D8UaHr
} wLPL9
} F"#bCnS
//负责部分文件的抓取 [bIdhG
**FileSplitterFetch.java M])Y|}wv8
*/ `$jc=ZLm
package NetFox; VJS|H!CH
~(aQ!!H6
cXFNX<
import java.io.*; 0 ML=]
import java.net.*; &7!&]kA+
Gmi4ffIb3
``)ys^V
public class FileSplitterFetch extends Thread { j8$*$|
3<1Uq3Pa
^<'5 V)
String sURL; //File URL Y'&A~/Adf
long nStartPos; //File Snippet Start Position `=RJ8u
long nEndPos; //File Snippet End Position #Sr_PEo _
int nThreadID; //Thread's ID -LJbx<'
boolean bDownOver = false; //Downing is over I#zrz3WU
boolean bStop = false; //Stop identical TggM/@k
FileAccessI fileAccessI = null; //File Access interface IExo#\0'6
m:59f9WXA
:D8V*F6P
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ='q:Io?T
{ ykH?;Xu
this.sURL = sURL; 8C#R
this.nStartPos = nStart; jwgXq(
this.nEndPos = nEnd; 7c1xB.g
nThreadID = id; Yj|Oy
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,`v)nwP
} fHCLsI
K4YpE}]u
'due'|#^
public void run() Dj'aWyW'
{ \?{nP6=
while(nStartPos < nEndPos && !bStop) ?~$0;5)QC
{ )Ge.1B$8h
"~0m_brf
V.vA~a
try{ t&T0E.kh*X
URL url = new URL(sURL); Ci0:-IS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U+F?b\
httpConnection.setRequestProperty("User-Agent","NetFox"); dElOy?v
String sProperty = "bytes="+nStartPos+"-"; \/g.`Pe
httpConnection.setRequestProperty("RANGE",sProperty); o_p#sdt"
Utility.log(sProperty); eEePK~%c
0W<:3+|n4
LFvKF.
InputStream input = httpConnection.getInputStream(); sy=M#WGS
//logResponseHead(httpConnection); /_5I}{
_]a8lr+_-
;,![Lar5L
byte[] b = new byte[1024]; "Lk-R5iFd
int nRead; @.;] $N&J
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #;sUAR?]
{ (lq7 ct
nStartPos += fileAccessI.write(b,0,nRead); fCdd,,,}
//if(nThreadID == 1) 0)`{]&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "K n JUXpl
} HgPRz C
u@tJu'X
6:O3>'n
Utility.log("Thread " + nThreadID + " is over!"); ! /;@kXN
bDownOver = true; Fk@A;22N
//nPos = fileAccessI.write (b,0,nRead); bmgK6OyVR
} pXf!8X&y
catch(Exception e){e.printStackTrace ();} x%ju(B>
} }CnqJ@>C5
} R("g ]
\>0%E{CR
99w;Q 2k
//打印回应的头信息 T+ey>[
public void logResponseHead(HttpURLConnection con) ,ef"S r
{ }'mVD^<+
for(int i=1;;i++) WJbdsPs
{ ?K%&N99c!
String header=con.getHeaderFieldKey(i); /fC@T
if(header!=null) -\6nT'P
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]#=43
Utility.log(header+" : "+con.getHeaderField(header)); H=Rqr
else xP%`QTl\
break; <3C~<
} #va|&QBZxM
} D%GB2-j R
3mKmd iD
/nEt%YYh;x
public void splitterStop() mL/]an@Y
{ g"vg {Q
bStop = true; )';Rb$<Qn
} 5$Lo]H*
M\O6~UFq!
Tap=K|b ]
} AoB~ZWq
jiQJ{yY
0f~7n*XH
/* u=NpL^6s<
**FileAccess.java 2<HG=iSf
*//文件访问(定位，写) I;H6E
package NetFox; d#P3 <
import java.io.*; CBw/a0Uck
EV{kd.=f
RU&,z3LEb
public class FileAccessI implements Serializable{ Gh}k9-L
,0+%ji^V
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~wG.'d]
RandomAccessFile oSavedFile; M,xhQ{eBY
long nPos; !R*%F
i(R&Q;{E^
l9"4"+?j<
public FileAccessI() throws IOException ,4W|e!
{ w#.Tp-AZ;\
this("",0); \pI)tnu6'U
} NX7(;02
w{uqy]
\l!^6G|c
public FileAccessI(String sName,long nPos) throws IOException \`?#V xz
{ ^9*FYV
oSavedFile = new RandomAccessFile(sName,"rw"); EWuuNf
this.nPos = nPos; xxxM
oSavedFile.seek(nPos); 0sq?;~U
} 3Mw\}q
^.bYLF
[0|g3K!A
public synchronized int write(byte[] b,int nStart,int nLen) UB[tYZ
{ JTbg8b
int n = -1; hz#S b~g
try{ lU]/nKyd
oSavedFile.write(b,nStart,nLen); %gj's-!!
n = nLen; (2J_Y*N~>
} n';"c;Ye)
catch(IOException e) 6J. [9#
{ AQkH3p/W
e.printStackTrace (); ZqKUz5M4
} *zoAD|0N
)=VSERs
)o!y7MTl
return n; 0{M=^96
} ;\(Wz5Ok&J
1(!w xJ
&4M0 S+.
} v&g(6~b_>
VsS.\1
:NB|r
/* v%RcwVt|
**SiteInfoBean.java 9^l[d<
*/ &t)dE7u5
package NetFox; c\GJfsVk
K"'W4bO#7
&8!*u3
public class SiteInfoBean { c%1<O!c
*&p`8:
g1U
private String sSiteURL; //Site's URL `P1jg$(eA
private String sFilePath; //Saved File's Path 2yqm$i9C
private String sFileName; //Saved File's Name AWlR" p2
private int nSplitter; //Count of Splited Downloading File [@D+kL*>
WK7=z3mu
U9:?d>7
public SiteInfoBean() V0hC[Ilr
{//nSplitter的缺省值为5 cgKK(-$ny
//default value of nSplitter is 5 ca>6r`
this("","","",5); c +Pg[1-
} `>:ozN#)\
[s?H3yQ.
A#9@OWV5f
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cJ9:XWW
{ l:NEK`>i
sSiteURL= sURL; (WT0j
sFilePath = sPath; }W&hPC
sFileName = sName; S.o 9AUv9
this.nSplitter = nSpiltter; v=Ep
aYQ!`mS::M
v5"5UPi-
} X\3IY:Q@T
_Y@'<S.
PAF2=
public String getSSiteURL() 1_vaSEov
{ KobNi#O+
return sSiteURL; J;+AG^U<
} TbyQ'MbUv
5=CLR
nA8]/r1k
public void setSSiteURL(String value) YpQ/ )fSEV
{ zjd]65P
sSiteURL = value; dtJaQ`
} +gb2>fei&
l'YpSO~l7
@W3fKF9*R
public String getSFilePath() r1:S8RT;H5
{ Ko%&~C_
return sFilePath; T xRa&1
} ]X4 A)4y
\ B 0xL,o<
K~$o2a e
public void setSFilePath(String value) )fSQTbB;0
{ k,0RpE
sFilePath = value; (bH*i\W
} [sG=(~BU
U(5(0r
>O[# 661
public String getSFileName() Zcd!y9]#
{ 31mY]Jve"
return sFileName; pE>~F
} U+sAEN_e k
O?Xg%k#
!Dp4uE:Pq
public void setSFileName(String value) YIs(Q
{ Qg
sFileName = value; btb-MSkO
} V.J[Uwf
d#7 z N
+:w9K!31-
public int getNSplitter() ?}^e,.M0?s
{ %)_R>.>
return nSplitter; Pz3jc|Ga
} :,<e
V/i&8UMw
-)@DH;[tb
public void setNSplitter(int nCount) 7SYU^GD
{ O6gI%Jdp
nSplitter = nCount; ?bbu^;2*f
} ?b, eZ+t
} cT^,[3i:c
#9z\Wblr
(_-<3)q4
/* !pl<
**Utility.java *{:FPmDU
*/ }_}C ^
package NetFox; >L#&L?#
~]?Q'ER
&s_O6cqgh
public class Utility { `9b/Q
k{Yj!C> #
VR5$[-E3
public Utility() $Hqm 09w
{ S:{hgi,T*
[r_,BH\nu
m *8[I
} O?NAbxkp
lwPK^)|}
//线程睡眠 I"*g-ji0
public static void sleep(int nSecond) /HH5Mn*
{ (qHI>3tpY
try{ n5"rSgUtE
Thread.sleep(nSecond); 2-nL2f!a{p
} cX"[#Em#
catch(Exception e) (i>VJr
{ Zeyhr\T
e.printStackTrace (); rFZB6A<(]
} 5~4I.+~8
} dsqqq,>Q
f33'2PYl
//日志 $6atr-Pb
public static void log(String sMsg) Y[Us"K`
{ [~?LOH
System.err.println(sMsg); 2S}%r4$n}
} qQ%zSJ?
;^xlDN
ftF?T.dx
public static void log(int sMsg) /ow/)\/}
{ |//cA2@.
System.err.println(sMsg); K)$.0S9d
} `ysPEwA|
} y!GjC]/
\\ M2_mT
Q?n} ~(%&
/* -cNh5~p=
**TestMethod.java b")&"o)G2W
*/ vp &jSfQ^
package NetFox; |332G64K
]"q[hF*PM
t`+x5*gW
public class TestMethod { gE(QVbh(
2#C!40j&\
QsI#Ae,O#;
public TestMethod() zTrAk5E
{ ///xx/weblogic60b2_win.exe o\h[K<^>)
try{ WaF<qhu*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -vwkvNn8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U*,8,C
SiteFileFetch fileFetch = new SiteFileFetch(bean); J]nb;4w
fileFetch.start(); eV^@kI4
} O[y.3>l[s
catch(Exception e){e.printStackTrace ();} IPa08/
LslQZ]3MY
`R0>;TdT
} i68'|4o
$4'I3{$
5.F.mUO
public static void main(String[] args) @no]*?Gpa
{ %m!o#y(hD`
new TestMethod(); h1G]w/.ws
} EonZvT-D=
} FIlw
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