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)); ;>%wf3e
} gL&)l!2Y
for(int i=0;i<nEndPos.length-1;i++) ',1[rWyc
{ N[I ?x5:u
nEndPos = nStartPos[i+1]; `[&%fTW+
} ck$>
nEndPos[nEndPos.length-1] = nFileLength; R"{P#U,HNO
} 5,BvT>zFY
} ( m7qc
h%5keiA
yb-4[C:i
//启动子线程 q#F+^)DD [
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xS;tmc
for(int i=0;i<nStartPos.length;i++) yuhY )T
{ Q?bC'147O
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tqpSir
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~i]4~bkH2
nStartPos,nEndPos,i); hGI5^!Cq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %NcBq3
fileSplitterFetch.start(); {Q)sR*d
} FzF#V=9lP
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %v0;1m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ";upu
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w3;T]R*
nEndPos = " + nFileLength); |+Xh ^E
// fileSplitterFetch[nPos.length-1].start(); hbSKlb0d
y"iK)SH
4YXp,U
//等待子线程结束 mln%Rd6u/
//int count = 0; S3Fj /2Q8
//是否结束while循环 s6DPb_,
boolean breakWhile = false; 9fYof
#+ {%>f
1I%niQv5t
while(!bStop) L+lX$k
{ HP=5a.
write_nPos(); YXg^t$
Utility.sleep(500); )"g @"LJ=
breakWhile = true; ?z3|^oU~d
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t1p[!53(
for(int i=0;i<nStartPos.length;i++) @vO~'Xxq!
{ Hn]6re
if(!fileSplitterFetch.bDownOver) 6ZQ$5PY
{ D77$aCt
breakWhile = false; bRJ]avR
break; ^vZu[m
} (hIe!"s*
} >}r 1A
if(breakWhile) lr[&*v?h
break; S-79uo
(\4YBaGd
/S9n!H:MT
//count++; &-KQ m20n
//if(count>4) `a8&7J(
// siteStop(); 91ec^g
} 1]aya(
,w,)n^
AQPzId*z
System.err.println("文件下载结束！"); 6-\C?w A
} ~2UmX'
catch(Exception e){e.printStackTrace ();} UdFYG^i
} k~]\kv=
w69G6G(
[bEm D
//获得文件长度 0C717
public long getFileSize() n*hRlL
{ MNX-D0`g
int nFileLength = -1; 6W'2w?qj?4
try{ CWkAc5
URL url = new URL(siteInfoBean.getSSiteURL()); zeuSk|O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h[]3#
httpConnection.setRequestProperty("User-Agent","NetFox"); lAAPV
^3nB2G.ax
\V*E:_w*
int responseCode=httpConnection.getResponseCode(); mnH1-}oL
if(responseCode>=400) >+S* Wtm5
{ % %QAC4
processErrorCode(responseCode); Ws[d.El
return -2; //-2 represent access is error wQU-r|
} r]%.,i7~8
'~76Y9mv
TzrU |D?
String sHeader; $I a-go2W
^Y^5 @x=
NTSKmCvQG
for(int i=1;;i++) {6*{P!H
{ u"zQh|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w&}UgtEm
//Utility.log(in.readLine()); kN*\yH|
sHeader=httpConnection.getHeaderFieldKey(i); ^j'vM\^`ml
if(sHeader!=null) ntF#x.1Pm
{ 0.!Q4bhD
if(sHeader.equals("Content-Length")) gR{.0e
{ q?oJ=]m"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g%d&>y?1r
break; "Oy&6rrr
} !B&1{
} G/8G`teAZ
else po+1
break; |y2cI,&
} D 3}e{J8
} |Vc:o_n7
catch(IOException e){e.printStackTrace ();} )h(yh50 B
catch(Exception e){e.printStackTrace ();} g$S<_$Iey
\4&FW|mx
Gp))1b';
Utility.log(nFileLength); ,lw<dB@7"5
XJf1LGT5
/J'dG%
return nFileLength; A\<WnG>xjP
} Y&DC5T]
fpvzx{2
E%>){Y)
//保存下载信息（文件指针位置） _:l<4u!
private void write_nPos() J""N:X!1
{ q,eXH8 x
try{ ;AgXl%Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); \J^|H@;(@
output.writeInt(nStartPos.length); QX393v!
for(int i=0;i<nStartPos.length;i++) V~qlg1h
{ ZBfB4<M9xS
// output.writeLong(nPos); zXg/.z]
output.writeLong(fileSplitterFetch.nStartPos); qbdv
output.writeLong(fileSplitterFetch.nEndPos); <S M%M?
} qxglA*/ [
output.close(); -%)8=
} rDWqJ<8
catch(IOException e){e.printStackTrace ();} W= \gPCo
catch(Exception e){e.printStackTrace ();} `'<&<P
} (6\ H~
[+v}V ,jb
D`uOBEX
//读取保存的下载信息（文件指针位置） Nh|QYxOP
private void read_nPos() s&*s9F
{ `=f1rXhI+1
try{ '|N9xLm
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #$9rH 2zd
int nCount = input.readInt(); o*WI*Fb'
nStartPos = new long[nCount]; a"0'cgB}
nEndPos = new long[nCount]; v:$Y |mh
for(int i=0;i<nStartPos.length;i++) jP|(y]!
{ TJp0^&Q
nStartPos = input.readLong(); :j0r~*z-
nEndPos = input.readLong(); *S4*FH;8
} {pNf&'
input.close(); T5di#%: s
} 2*1s(Jro
catch(IOException e){e.printStackTrace ();} ~2*8pb 4
catch(Exception e){e.printStackTrace ();} $:MO/Suz{
} B%Spmx8
j8gi/07l
1~#p3)B
private void processErrorCode(int nErrorCode) - '5OX/Szq
{ /.aDQ>
System.err.println("Error Code : " + nErrorCode); +EBoFeeIG
} onj:+zl
x?|
P9D'L{yS/x
//停止文件下载 Wc)f:]7
public void siteStop() ;1 02ddRV
{ (PN!k0Y
bStop = true; 0Ie9T1D=
for(int i=0;i<nStartPos.length;i++) .v:K`y;f\(
fileSplitterFetch.splitterStop(); fX2PteA0qX
S?_ ;$Cn
OVm $
} pJE317 p'
} 4!dN^;Cb
//负责部分文件的抓取 r:Xui-
**FileSplitterFetch.java L?n*b
*/ ~IKPi==@,
package NetFox; G&Sp }
cEd!t6Z
]='E&=nc
import java.io.*; {<- BU[H
import java.net.*; O5Xu(q5+
=/rIXReY
w(9.{zF|vQ
public class FileSplitterFetch extends Thread { +cVnF&@$
j5:{H4?
{>cO&eiCt
String sURL; //File URL ivbuS-f=r
long nStartPos; //File Snippet Start Position O`hOVHDQ
long nEndPos; //File Snippet End Position jo4*,B1x
int nThreadID; //Thread's ID @M-+-6+
boolean bDownOver = false; //Downing is over 2|)3Ly9
boolean bStop = false; //Stop identical FPu"/4v&
FileAccessI fileAccessI = null; //File Access interface =,~h]_\_
98os4}r
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /)PD+18
{ )[>b7K$f
this.sURL = sURL; 8]N+V:
this.nStartPos = nStart; mq?5|`
this.nEndPos = nEnd; RYaf{i`
nThreadID = id; <Dw`Ur^X5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !RnO{FL
} p_jDnb#
!ldb_*)h
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public void run() 1;[\xqJ
{ qlSc[nEk
while(nStartPos < nEndPos && !bStop) DH_Mll>
{ @l^=&53T
u5EHzoq
XX,iT~+-
try{ 0*"auGuX
URL url = new URL(sURL); XnQo0 R.PW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0f 1Lu) 2
httpConnection.setRequestProperty("User-Agent","NetFox"); pCNihZ~
String sProperty = "bytes="+nStartPos+"-"; M ,8r{[2
httpConnection.setRequestProperty("RANGE",sProperty); ":*PC[)W
Utility.log(sProperty); ;jTP|q?|{
++:vO
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InputStream input = httpConnection.getInputStream(); ubIGs|p2c
//logResponseHead(httpConnection); Cd#>,,\z
92GO.xAD?
ho_;;y
byte[] b = new byte[1024]; 5yO6szg
int nRead; j3rBEQ,R
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) OZ1+`4 v
{ OedL?4
nStartPos += fileAccessI.write(b,0,nRead); tH<v1LEZN
//if(nThreadID == 1) pAYH"Q6~)I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dvk?A$
} tqIz$84G
. oUaq|O
*tjE#TW
Utility.log("Thread " + nThreadID + " is over!"); qbkvwL9
bDownOver = true; @M?N[LG
//nPos = fileAccessI.write (b,0,nRead); a8-2:8Su
} t#~r'5va
catch(Exception e){e.printStackTrace ();} !Ljs9 =UF
} #:Di1I9<O7
} su(y*187A
0iW]#O/
&eT)c<yhyK
//打印回应的头信息 jpqq>Hbg_
public void logResponseHead(HttpURLConnection con) I;L$Nf{v
{ bh?Vufd%)
for(int i=1;;i++) uYS?# g
{ =8j;!7p
String header=con.getHeaderFieldKey(i); pc5-'; n
if(header!=null) TdP_L/>|J
//responseHeaders.put(header,httpConnection.getHeaderField(header)); E)>~0jv
Utility.log(header+" : "+con.getHeaderField(header)); W?G4\ubM3<
else abUn{X+f~
break; ( =->rP
} wYhWRgP
} y>u+.z a|
gy _86y@
8<k0j&~J
public void splitterStop() V#|#% 8
{ R)t"`'6|
bStop = true; dZRz'd
} f 5_n2
L._I"g5 H9
J /'woc
} q,2]]K7y
`|i #)
B}gi /
/* nbw&+dcJ8
**FileAccess.java t/_w}
*//文件访问(定位，写) Fm{Ri=X<:
package NetFox; f!*b8ND^R
import java.io.*; 5SK{^hw
?};}#%971
U n2xZ[4
public class FileAccessI implements Serializable{ =+97VO(w]G
NDU,9A.P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C+,;hj
RandomAccessFile oSavedFile; #18H Z4N
long nPos; xzy7I6X
,Vt7Kiu
' G-]>
public FileAccessI() throws IOException a|32Pn
{ Rs{L
this("",0); Qwk
} gCgMmD=AZ
18Vtk"j
>c\'4M8Cz
public FileAccessI(String sName,long nPos) throws IOException i=reJ(y-
{ ]~87v
oSavedFile = new RandomAccessFile(sName,"rw"); xg'z_W
this.nPos = nPos; ME1lQ7E4B
oSavedFile.seek(nPos); "4H&wHhT!
} 3ZU`}
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&m`1lxT
public synchronized int write(byte[] b,int nStart,int nLen) vML01SAi
{ ,2[laJ
int n = -1; Tm_AoZH
try{ sZPPS&KoP3
oSavedFile.write(b,nStart,nLen); /lm;.7_J+
n = nLen; K-)_1
} q>%KIBh(
catch(IOException e) wtetB')yD
{ n%3rv?m7
e.printStackTrace (); 2JYyvJ>
} /Bid:@R
NUEy0pLw
OTL=(k
return n; {~k/xM.-
} bec n$R
$f*N
ln'7kg
} &'N{v@Oi)
d%81}4f:
c7q1;X{:
/* %(Nu"3|$K=
**SiteInfoBean.java ._~_OVU
*/ qWHH% L;
package NetFox; /0d_{Y+9
vO%n~l=
p8oOm>B96n
public class SiteInfoBean { R(kr@hM
_,=A\C_b@
@~U: |h
private String sSiteURL; //Site's URL 92WvD
private String sFilePath; //Saved File's Path :qc@S&v@]
private String sFileName; //Saved File's Name U GQ{QH
private int nSplitter; //Count of Splited Downloading File 8*H-</ =
vmvk
m7zen530
public SiteInfoBean() rF2`4j&!
{//nSplitter的缺省值为5 x %L2eXL
//default value of nSplitter is 5 k8F<j)"
this("","","",5); I0(BKMp&
} (8qMF{
5CueD]
>:Na^+c
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y]P';C_eP
{ wP/&k`HQ#i
sSiteURL= sURL; 'LpJ:Th
sFilePath = sPath; `g<@F^x5
sFileName = sName; 7u6o~(
this.nSplitter = nSpiltter; Ha1E /b]K
84DneSpHsp
ZvpcjP
} sczN0*w&C
,u#uk7V
=GL}\I
public String getSSiteURL() j5|_SQOmt
{ LUl6^JU
return sSiteURL; |o6 h:g
} XpdDIKMmE
#25Z,UU
6B)(kPW
public void setSSiteURL(String value) =\B{)z7@6D
{ 9 #TzW9
sSiteURL = value; ,G!M?@Q
} ,3.E]_3xX
n`2d
3xxQL,FV
public String getSFilePath() pzbR.L}'D
{ 8V>j-C
return sFilePath; .mn`/4
} 53J!iNnXT6
WW{5[;LYiB
:.'<ndM
public void setSFilePath(String value) PBbJfm
{ yQ}$G ,x
sFilePath = value; l)[\TD
} n1 =B
q&Y'zyHLP
QM2Y?."#
public String getSFileName() ;n%SjQ'%
{ 8>x!n/z)
return sFileName; '3 w=D )
} u=z$**M^
:6S!1roi
1 !bODd
public void setSFileName(String value) Y (x_bJ
{ %obR2%
sFileName = value; .+MJ' bW
} <+o-{{E[
jl;_lcO
&PaqqU.
public int getNSplitter() dF:@BEo
{ QO0}-wZR
return nSplitter; ']Gqa$(YC
} k"&loh
'DO^($N
_ui03veA1
public void setNSplitter(int nCount) 5XySF #
{ `E+)e?z
nSplitter = nCount; f uQbDb&
} $h`(toTyF
} k"\%x=#
T$T:~8tK3
Aayh'xQ
/* gKeqf-UWKJ
**Utility.java 3sIW4Cs7)U
*/ MGze IrV
package NetFox; usH9dys,
I_6NY,dF
,yus44w[
public class Utility { M.$Li#So,
g@wF2=
qYR $5
public Utility() N-`Vb0;N
{ "RMBV}<T
>/mi#Y6
l*>t@:2J
} (|)`~z
c[\ :^w^I6
//线程睡眠 4YDK`:4I~
public static void sleep(int nSecond) ~XN--4%Q
{ =}>wxO
try{ x=T`i-M
Thread.sleep(nSecond); ma9q?H#X
} [ -"o5!0<
catch(Exception e) i!+D ,O
{ BLZ#vJR
e.printStackTrace (); 6r! Y ~\@
} 4 AZ~<e\
} TPo%zZo
z%$ E6Im
//日志 oFM\L^Y?$$
public static void log(String sMsg) psyxNM=dN#
{ 7ksh%eV
System.err.println(sMsg); IhnHNY]<g
} LOQoi8j
c.-h'1
A}WRpsA9
public static void log(int sMsg) _a1 =?
{ 1c_gh12
System.err.println(sMsg); q9fCoz
} 'QGacV
} B?Ac
KwK[)Cvv
x{{QS$6v
/* !$Aijd s5
**TestMethod.java ]T|9>o!
*/ Xou1X$$z
package NetFox; [p[nK=&r
j(^ot001%v
{6{y"8
public class TestMethod { wI.i\S
ASmMj;>UM
f0p+l-iEv
public TestMethod() Z0&^U#]
{ ///xx/weblogic60b2_win.exe 7'u<)V
try{ T'\B17 :*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); RrrW0<Ed
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z|;<:RKWY
SiteFileFetch fileFetch = new SiteFileFetch(bean); {Hncm
fileFetch.start(); ?_mcg8A@@*
} :$k':0 n
catch(Exception e){e.printStackTrace ();} J-*&&
OQzJRu)mF#
qu]ch&"?U
} }$M 2XF
o?nlnoe
r@C2zF7
public static void main(String[] args) ZeewGa^r
{ zogtIn)
new TestMethod(); 1d/-SxhZ
} *Q2;bmIc
} ~\= VSwJ
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