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)); i-/'F
} (sPZ1Fr\o
for(int i=0;i<nEndPos.length-1;i++) -EL"Sv?
{ pWQ?pTh
nEndPos = nStartPos[i+1]; (2a~gQGD
} "2Ye\#BU6
nEndPos[nEndPos.length-1] = nFileLength; X#Hs{J~@p
} kszYbz"
} Li7/pUq>}!
LL:B H,[
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//启动子线程 jdoI)J@9H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; < Gu s9^_
for(int i=0;i<nStartPos.length;i++) \9 ^wM>U
{ UHxXa*HyI
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GadD*psD2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), sM-k,0z
nStartPos,nEndPos,i); ,>e<mphM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &{7%VsTB
fileSplitterFetch.start(); W}T$Z
} *d)B4qG
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;%Z)$+Z_)<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3 i>uKU1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", LdRLKE<'e
nEndPos = " + nFileLength); ="XxS|Mq3
// fileSplitterFetch[nPos.length-1].start(); Q+#, VuM
G:A` n;E0
uS<&$JH
//等待子线程结束 X\flx~
//int count = 0; JZai{0se
//是否结束while循环 9v/1>rziE
boolean breakWhile = false; ON!1lS
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RX#:27:
while(!bStop) 3ne=7Mj
{ )kg^.tP
write_nPos(); r_Xk:
Utility.sleep(500); )2:d8J\
breakWhile = true; fkYa
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MF>?! !
for(int i=0;i<nStartPos.length;i++) hGzj}t W8d
{ 0naegy?,
if(!fileSplitterFetch.bDownOver) l$z-'
{ V<(cW'zA/
breakWhile = false; M`S >Q2{
break; 6&h,eQ!
} B6|=kl2C
} bY]aADv\
if(breakWhile) A.(Z0,S-i
break; m[%&KW(
X$J
d+z8^$z"
//count++; OCF=)#}qd
//if(count>4) a^|mF# z
// siteStop(); 0urQA_JC
} o2&mhT
,@(lYeD"
z!?xz
System.err.println("文件下载结束！"); $1/yc#w u
} |"\A5v|1
catch(Exception e){e.printStackTrace ();} h\:"k_u#
} 7!z0)Ai_>=
!~PV\DQN
vr2tMD
//获得文件长度 W!htCwnkF
public long getFileSize() 2gukK8R$
{ >~2oQ[n
int nFileLength = -1; 9Yd<_B#
try{ Ptn0;GC
URL url = new URL(siteInfoBean.getSSiteURL()); /_>S0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $xNZ.|al
httpConnection.setRequestProperty("User-Agent","NetFox"); G4]T
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arRbq!mO
int responseCode=httpConnection.getResponseCode(); ZC@Pfba[`
if(responseCode>=400) <D!"<&N
{ !-p5j3A4L
processErrorCode(responseCode); >pUR>?t"
return -2; //-2 represent access is error CKy' 8I9
} 8)/d8@
FL9Dz4
O_*%_S}F&
String sHeader; 3Vs8"BFjz
0.=dOz r
N-y[2]J90
for(int i=1;;i++) "V}WV!w
{ UM3}7|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &r doMc;
//Utility.log(in.readLine()); X8"4)IZ3
sHeader=httpConnection.getHeaderFieldKey(i); Z`T]jm-3
if(sHeader!=null) =YOq0
{ 5$d>:" >
if(sHeader.equals("Content-Length")) /&_$+Iun
{ 2.qEy6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b<n*wH
break; jH({Qc,97
} fX2sjfk
} #Ipi3
else Vo"Wr>F
break; 8,7^@[bzXx
} Y;-$w|&P>
} E{k$4
catch(IOException e){e.printStackTrace ();} 9$$dSN\&
catch(Exception e){e.printStackTrace ();} ]{s0/(EA
TD!--l*gL
SYkwM6
Utility.log(nFileLength); s'b 4Me
UQc!"D
FC@h6\+a
return nFileLength; ?(0=+o(`
} qILb>#
C3)*Mn3%P
N:x--,2
//保存下载信息（文件指针位置） [MhKR }a
private void write_nPos() +saXN6
{ ;-#2p^
try{ %PM&`c98z7
output = new DataOutputStream(new FileOutputStream(tmpFile)); "ngULpb{R
output.writeInt(nStartPos.length); JlR$"GU
for(int i=0;i<nStartPos.length;i++) ~@=(#tO.
{ n+MWny
// output.writeLong(nPos); =h0vdi%{
output.writeLong(fileSplitterFetch.nStartPos); <-;/,uu
output.writeLong(fileSplitterFetch.nEndPos); fG9 ;7KG
} @<(4J
output.close(); $>Qq 7
} g&z8t;@
catch(IOException e){e.printStackTrace ();} E@,m+
catch(Exception e){e.printStackTrace ();} N,W ?}
} 'HKDGQl`
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GXC,p(vbE
//读取保存的下载信息（文件指针位置） YLJ^R$pi
private void read_nPos() ckGmwYP9
{ 6S`0<Z;;/
try{ cX7 O*5C
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }D>#AFs6#
int nCount = input.readInt(); o3]Lrzh
nStartPos = new long[nCount]; f7YBhF
nEndPos = new long[nCount]; h4Wt oE>i
for(int i=0;i<nStartPos.length;i++) s@Dln Du.
{ B6=?Qp/f
nStartPos = input.readLong(); v%:VV*MxF
nEndPos = input.readLong(); V'hb 4}@
} $vrkxn
input.close(); c+D<
} wXjidOd$
catch(IOException e){e.printStackTrace ();} \?SvO
catch(Exception e){e.printStackTrace ();} e,N}z
} is }>+&_
]Hp>~Zvbb
G/*;h,NbNr
private void processErrorCode(int nErrorCode) DA1?M'N
{ B*Q9g r
System.err.println("Error Code : " + nErrorCode); e:%|.$4OG
} H2H`7 +I,
*Nm$b+
Mg#yl\v
//停止文件下载 I4W@t4bZ
public void siteStop() !O,Sq/=.
{ o]EL=j
bStop = true; vJLGy]
for(int i=0;i<nStartPos.length;i++) c {/J.
fileSplitterFetch.splitterStop(); > vdmN]
>H^#!eaqw
e2f+Fv 9
} v3#,Z!
} 8Qo'[+4;
//负责部分文件的抓取 6<EGH*GQ$
**FileSplitterFetch.java q`,%L1c4
*/ [Ur\^wS
package NetFox; Y{D%v
~wa6S?
Z:dp/M}
import java.io.*; P#O2MiG
import java.net.*; f(Y_<%
/a'1W/^2
N0H=;CIQ
public class FileSplitterFetch extends Thread { V"m S$MN
&\1n=y
#l ZK_N|1x
String sURL; //File URL N+'j on}U
long nStartPos; //File Snippet Start Position _Ao$)Gu)
long nEndPos; //File Snippet End Position "$XX4w M
int nThreadID; //Thread's ID V:$+$"|
boolean bDownOver = false; //Downing is over s bj/d~$N
boolean bStop = false; //Stop identical H T|DT
FileAccessI fileAccessI = null; //File Access interface Keozn*fzI
tLBtE!J$[
} vmRm*8z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )\|+G5#`
{ ]QhTxrF"
this.sURL = sURL; W7^[W.
this.nStartPos = nStart; 5BJE
this.nEndPos = nEnd; -~mgct5
nThreadID = id; )V\@N*L`ik
fileAccessI = new FileAccessI(sName,nStartPos);//定位 TWzLJ63*
} 1h&`mqY)L.
?3=G'Ip5n
%WgN+A0
public void run() b~J)LXj]w
{ &}r"Z?f)
while(nStartPos < nEndPos && !bStop) 27EK+$
{ @eJCr)#}
<.Ws; HN}
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try{ j-":>}oW2.
URL url = new URL(sURL); ` y\)X C7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hW~.F
httpConnection.setRequestProperty("User-Agent","NetFox"); Ttt'X<9
String sProperty = "bytes="+nStartPos+"-"; uMJ\
httpConnection.setRequestProperty("RANGE",sProperty); /]_t->
Utility.log(sProperty); Ot2o=^Ng
} o%^ Mu B
Y !?'[t
InputStream input = httpConnection.getInputStream(); W6&vyOc
//logResponseHead(httpConnection); Ks-$:~?5":
b6bs .
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byte[] b = new byte[1024]; 9af.t
int nRead; )S caT1I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {_QdB;VwH
{ !y= R)k
nStartPos += fileAccessI.write(b,0,nRead); ;V xRaj?
//if(nThreadID == 1) i"WYcF|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wI$a1H
} Z!)~?<gcq:
pk :P;\
\84t\jKR
Utility.log("Thread " + nThreadID + " is over!"); <kak9 6A
bDownOver = true; JE=t e(a
//nPos = fileAccessI.write (b,0,nRead); zx3gz7>k;
} =dmr,WE
catch(Exception e){e.printStackTrace ();} *MP.YI:h
} bGPE0}b
} E>!=~ 7.
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fpD$%.y'J
//打印回应的头信息 $ik*!om5
public void logResponseHead(HttpURLConnection con) Fx9-A8oIR
{ S<tw5!tJ
for(int i=1;;i++) /wV|;D^ )
{ \N,ox(f?gW
String header=con.getHeaderFieldKey(i); 9)Fx;GxL
if(header!=null) tt"<1 z@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); NRi5 Vp2=
Utility.log(header+" : "+con.getHeaderField(header)); c-a,__c?hx
else a=iupXre9
break; b/wpk~qi
} |9CikLX)7
} I//=C6
g.lTNQm$u
*'%V}R[>
public void splitterStop() ^*K=wE}AG
{ OtG\Uw8
bStop = true; *g/klK
} =[6^NR(
a`xq h2P
#B `?}a=
} ;_o]$hV|
ekM? '9ez
YuXJT*
/* T(b9b,ov)
**FileAccess.java x:Y9z_)O
*//文件访问(定位，写) ;G[V:.o-
package NetFox; 4,9$udiGY
import java.io.*; 6Sr]<I +:
fab'\|Y
*FlPGBjJ
public class FileAccessI implements Serializable{ +iVEA(0&$
p"g|]@m
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !?2)apM
RandomAccessFile oSavedFile; hAGHb+:
long nPos; _?{7%(C
x9_mlZ
bc)>h!'Y
public FileAccessI() throws IOException 2hh8G5IaQ
{ iOE. .xA:
this("",0); @:lM|2:
} nM,:f)z
O'y8q[2KE
i+_LKHQN
public FileAccessI(String sName,long nPos) throws IOException SQKhht`M
{ @<.@X*#I
oSavedFile = new RandomAccessFile(sName,"rw"); Gw M:f/eV
this.nPos = nPos; (3#PKfY+
oSavedFile.seek(nPos); 5KCB^`|b>t
} nxLuzf4U5
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public synchronized int write(byte[] b,int nStart,int nLen) 9!FX*}dC
{ !jCgTo y
int n = -1; K1& QAXyP
try{ 1!#85SMx
oSavedFile.write(b,nStart,nLen); %y1!'R:ZW
n = nLen; jc^QWK*q
} Lb*KEF%s
catch(IOException e) ^ Ltho`
{ -yqsJGY
e.printStackTrace (); >I5:@6 Z
} B9v>="F
T1LYJ]5
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return n; _z\/{
} /d`"WK,
^^y eC|~N:
fgLjF,Y
} \}jMC
_fAgp_)
Z8$}Rpo
/* n 8cA8<
**SiteInfoBean.java v2T2/y%
*/ lCi{v.
package NetFox; mU'<:gL+
RNg?o[S
96=<phcwN[
public class SiteInfoBean { gI+8J.AG=
FG?Mc'r&
la!]Y-s)'4
private String sSiteURL; //Site's URL 8@3K, [Mo
private String sFilePath; //Saved File's Path sI ,!+
private String sFileName; //Saved File's Name ~9X^3.nI
private int nSplitter; //Count of Splited Downloading File @AyteHK
\Mf>X\}
PEMkx"h+
public SiteInfoBean() 9 {4yC9Oz>
{//nSplitter的缺省值为5 O-iE0t
//default value of nSplitter is 5 4{VO:(geZ
this("","","",5); /y$Omc^
} hor7~u+
d} >Po%r:
bIQ,=EA1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) x4_IUIgh
{ qJey&_
sSiteURL= sURL; }@DCcf$<
sFilePath = sPath; )SV.|
sFileName = sName; j=\h|^gA
this.nSplitter = nSpiltter; WI8}_){ d
1? >P3C
SzULy >e
} ou,[0B3n0
oXPA<ef o
m</m9h8
public String getSSiteURL() iFI74COam
{ #]#9Xq
return sSiteURL; x*7@b8J
} Q>niJ'7WF
(?FH`<
[%W'd9`>
public void setSSiteURL(String value) Ufr@j` *
{ pR0[qsQM
sSiteURL = value; ,Oo`*'a[o7
} NvK9L.K
0K!3Ny9(
eJDZ|$
public String getSFilePath() z^Hc'oVXj:
{ WQ|:TLQ
return sFilePath; J^!;$Hkd
} ;vx5 =^7P
OL'Ito
P.~UUS
public void setSFilePath(String value) | dQ>)_
{ W4$o\yA]
sFilePath = value; (d9~z
} ' jciX]g
MK< y$B{}
('J/Ww<
public String getSFileName() WMbkKC.{J
{ /:|vJ|dJ
return sFileName; >P6"-x,["
} awLvLkQb{
a~o<>H
XF`2*:7
public void setSFileName(String value) )f8>kz(
{ h]7_ N,
sFileName = value; c:Ua\$)u3,
} h>Kx
,EqQU|
*v<f#hB"
public int getNSplitter() kk4 |4
{ #G9 W65f
return nSplitter; sz7*x{E
} kc'$4 J4Tw
!j~wAdHk
DP_b9o \5
public void setNSplitter(int nCount) Iix,}kzss
{ r&=ulg
nSplitter = nCount; Bfb~<rs[
} ct+F\:e
} $QbJT`,mr
q~{) {t;
c r=Q39{
/* gC7!cn
**Utility.java `Fqth^RK?p
*/ RB>=#03
package NetFox; K)SWM3r
#*A'<Zm
/<[0o]
public class Utility { >a3m!`lq
q~`hn(S
Z[O hZ 9
public Utility() eqtZU\GI>
{ s.1F=u9a
7w )?s@CD
d<c29Y
} Omd;
ss^a=?~
//线程睡眠 tFU4%c7V
public static void sleep(int nSecond) k@xinK%O{
{ EKc<|e,F
try{ .jRI $vm
Thread.sleep(nSecond); =<\22d5L
} R~<N*En~
catch(Exception e) :>-zT[Lcn
{ XQ1]F{?/H
e.printStackTrace (); 18$d-[hX
} ]w*"KG!(
} q@.>eB'92P
IIk_!VzT
//日志 VuLb9Kn
public static void log(String sMsg) \zd[A~!
{ u%-]-:c
System.err.println(sMsg); pl8b&bLzi
} hs6pp/h>
M+"6VtZH
#p+iwW-
public static void log(int sMsg) HDm]njF%qQ
{ 2gWR2 H@
System.err.println(sMsg); wd:Yy
} ~[H8R|j "
} h!tpi`8\z
e;i 6C%DB
T;M ;c.U
/* Om.%K>V
**TestMethod.java /gAT@Vx
*/ ^f[6NYS?
package NetFox; P9!awLM-
he|Q(?
D:`Q\za
public class TestMethod { Mi]^wCF
$(}rTm
w_"d&eYdg0
public TestMethod() `2>p#`
{ ///xx/weblogic60b2_win.exe f )Lcs
try{ o Mz{j:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ry95a%&/s
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); NuOA'e+i
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3a:Hx| Yg
fileFetch.start(); 8Z!%rS
} ,ye}p1M
catch(Exception e){e.printStackTrace ();} 8T+9 fh]I
c5p,~z_Dtu
{@X>!]
} j$T12
AojL4H|
y\v#qFVOZ
public static void main(String[] args) Y:CX RU6eD
{ l8~(bq1
new TestMethod(); izSX
} I`{3I-E
} 9!AvsC9
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