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)); CeOA_M
} Go:(R {P
for(int i=0;i<nEndPos.length-1;i++) !nJl.Y$
{ 3)CIqN
nEndPos = nStartPos[i+1]; aynaV
} 2/t;}pw8
nEndPos[nEndPos.length-1] = nFileLength; j>\rs|^O
} \hI?XnL#
} 'xai5X
6J JA"] `
S}h d,"I
//启动子线程 Z R=[@Oi
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2uT6M%OC
for(int i=0;i<nStartPos.length;i++) ]smu~t0\
{ :,v(lq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v,Z]Vqk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (ot56`,k
nStartPos,nEndPos,i); .eVX/6,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gn/]1NNfR
fileSplitterFetch.start(); ?&,6Y'"
} SfPQ;s'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3k>#z%//
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !wd wo0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", wDoCc:
nEndPos = " + nFileLength); (t5y$bc
// fileSplitterFetch[nPos.length-1].start(); }yrs6pQ
zb[kRo&a0W
g%]<sRl:-
//等待子线程结束 PCgr`($U
//int count = 0; ]Z\W%'q+
//是否结束while循环 l}-k>fug
boolean breakWhile = false; ziO(`"v
[cEGkz
(JdheCq!x
while(!bStop) Mi(6HMA.SF
{ @VOegf+N
write_nPos(); ^J^~5q8
Utility.sleep(500); ?xMTO
breakWhile = true; !.V_?aYi8
gU&+^e >
2<n18-|OQ
for(int i=0;i<nStartPos.length;i++) ^)Y3V-@t
{ &Q"vXs6Gt
if(!fileSplitterFetch.bDownOver) Brs}
{ bvZD@F`2
breakWhile = false; Zp_j\B
break; "#0P*3-c
} RWM~7^JA
} p}!)4EI=
if(breakWhile) 5z3WRg
break; 3HP { a
_a"| :kX
6K8v:yYPa
//count++; 6?US<<MQ
//if(count>4) mP15PZ
// siteStop(); $(0<T<\
} n;xzjq-
)q4nyT>M
>a2[P"
System.err.println("文件下载结束！"); .^F&6'h1H
} U{lf$
catch(Exception e){e.printStackTrace ();} I;_T_m4.q
} >#mKM%T2MJ
RYC%;h
ZT/f
//获得文件长度 |mWSS'7fI
public long getFileSize() j+AZ!$E
{ W6EEC<$JL
int nFileLength = -1; twldwuN
try{ " @""
URL url = new URL(siteInfoBean.getSSiteURL()); ^qC.bv]&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 75R4[C6T
httpConnection.setRequestProperty("User-Agent","NetFox"); og+Vrd
mGP%"R2X
h \`(
int responseCode=httpConnection.getResponseCode(); O\yYCi(
if(responseCode>=400) 6z~ [Ay
{ 3ZSU^v
processErrorCode(responseCode); }*-fh$QJ
return -2; //-2 represent access is error RmKbnS$*q
} Z9% u,Cb
Pk5\v0vkg
:Zq?V`+M
String sHeader; 5)k/4l '
L!/{Z
[.$%ti*!
for(int i=1;;i++) {#z47Rz
{ ]+qd|}^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g_tEUaiK
//Utility.log(in.readLine()); p'@z}T?F
sHeader=httpConnection.getHeaderFieldKey(i); h;} fdk
if(sHeader!=null) ZZ!6O/M
{ 'i3-mZ/|8
if(sHeader.equals("Content-Length")) O@HD'
{ KU+u.J
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l&] %APL
break; R"t2=3K
} T72Z<h|<
} Avljrds+7
else 5c%Fb:BW=
break; h=YTgJ
} z:dW'U?1
} J$jLGy&'
catch(IOException e){e.printStackTrace ();} X&49C:jN
catch(Exception e){e.printStackTrace ();} @{<^rLt
5 8U[IGs(
n~w[ajC/
Utility.log(nFileLength); oM#+Z qP
u,YmCEd_V
~$ ?85
return nFileLength; <Z~Nz>'r
} |z}VP-L
.bh7
2Z^p)
//保存下载信息（文件指针位置） 8193d%Wb
private void write_nPos() @1pfH\m
{ yMgS0
try{ \!>qtFT
output = new DataOutputStream(new FileOutputStream(tmpFile)); eeBw\f0
output.writeInt(nStartPos.length); 6_9@s*=d>
for(int i=0;i<nStartPos.length;i++) Dg ~k"Ice
{ 3<a|_(K
// output.writeLong(nPos); Esj1Vv#
output.writeLong(fileSplitterFetch.nStartPos); ] TZ/=Id
output.writeLong(fileSplitterFetch.nEndPos); 11A;z[Zk
} G-o6~"J\
output.close(); -"Nvu
} YB{'L +Wbw
catch(IOException e){e.printStackTrace ();} h2+"e# _
catch(Exception e){e.printStackTrace ();} KlwBoC/{K
} U?:?NC=1{
O6q5qA
f.vJJa
//读取保存的下载信息（文件指针位置） <\ ".6=E#W
private void read_nPos() 7.yCs[Z
{ ? EhIK
try{ -3y $j+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _*t75e$-
int nCount = input.readInt(); [A;0IjKam
nStartPos = new long[nCount]; P!&yYR\
nEndPos = new long[nCount]; e&<=+\ul
for(int i=0;i<nStartPos.length;i++) @GQtyl;q
{ b^P\Kky
nStartPos = input.readLong(); Ob|tA
nEndPos = input.readLong(); xCu\jc)2
} ~!Rf5QA85
input.close(); [XA:pj;rg'
} vcOw`oS
catch(IOException e){e.printStackTrace ();} \tU[,3
catch(Exception e){e.printStackTrace ();} ZzT"u1,&
} ZZeF1y[q
yW}x
_tnoq;X[
private void processErrorCode(int nErrorCode) /EVXkf0
{ |[/XG2S
System.err.println("Error Code : " + nErrorCode); |5BvVqn
} clT[?8*
'L%)B-,n
c#fSt}J>C
//停止文件下载 - l0X]&Ex
public void siteStop() <Um5w1
{ cw~-%%/
bStop = true; Ige*tOv2
for(int i=0;i<nStartPos.length;i++) RE;)#t?K
fileSplitterFetch.splitterStop(); llpgi,-=
r)dXcus
T'14OU2N{Y
} (6)X Fp&
} "(;t`,F
//负责部分文件的抓取 ;Z&w"oSJ
**FileSplitterFetch.java 7C@m(oK
*/ *.-qbwOg
package NetFox; .`h:1FP8
+L=a\8Ep
2 3A)^j
import java.io.*; S<++eu
import java.net.*; !!v9\R4um
Q3LScpp
`S]DHxS
public class FileSplitterFetch extends Thread { 6?l|MU"Q.
~:UAL}b{\~
Rap_1o9#\
String sURL; //File URL <'P+2(Oi
long nStartPos; //File Snippet Start Position T FK#ign
long nEndPos; //File Snippet End Position HhUk9 >7
int nThreadID; //Thread's ID tHH @[E+h
boolean bDownOver = false; //Downing is over t)l^$j!h@
boolean bStop = false; //Stop identical chU,));F
FileAccessI fileAccessI = null; //File Access interface arn7<w0
o{MmW~/o&
v<]$,V]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9E
{ | Fk9ME
this.sURL = sURL; hJoh5DIE95
this.nStartPos = nStart; 4~0@(3
this.nEndPos = nEnd; r 4+%9)
nThreadID = id; TmgSV#G
fileAccessI = new FileAccessI(sName,nStartPos);//定位 J/A UOInh
} 6p~8(-nG
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public void run() b5UIX Kim
{ g;</|Z
while(nStartPos < nEndPos && !bStop) lUM-~
{ I oC}0C7
/h K/t;
iaQ3mk#
try{ m/1;os5+8
URL url = new URL(sURL); R-BN}ZS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x1 1ug
httpConnection.setRequestProperty("User-Agent","NetFox"); !MD uj
String sProperty = "bytes="+nStartPos+"-"; l| QQ
httpConnection.setRequestProperty("RANGE",sProperty); 20BU;D3
Utility.log(sProperty); zWq&HBs
BGL-lJrG
\7tJ)[0aF
InputStream input = httpConnection.getInputStream(); Jgzg[6
//logResponseHead(httpConnection); h1QrFPQnu
7j{63d`2
gib;> nuBK
byte[] b = new byte[1024]; ]iH~1[
int nRead; jsIT{a*]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) SHUn<+/e
{ jRSY`MU}t+
nStartPos += fileAccessI.write(b,0,nRead); zFO#oW,D
//if(nThreadID == 1) %`^{Hh`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sj%\lq
} Xwk_QFv3
M[5fNK&nD
4mwAo
Utility.log("Thread " + nThreadID + " is over!"); uBxs`'C
bDownOver = true; P&9&/0r=_
//nPos = fileAccessI.write (b,0,nRead); =_9grF-
} 4*_.m9{
catch(Exception e){e.printStackTrace ();} $or8z2d1
} 5^GrG|~
} qM0Df0$?x
A&qZ:&(OM
l=ZX9<3
//打印回应的头信息 JReJlDu
public void logResponseHead(HttpURLConnection con) } !RBH(m%
{ 8H2A<&3i
for(int i=1;;i++) a3E.rr;b
{ }Uunlz<
String header=con.getHeaderFieldKey(i); LE4P$%>H
if(header!=null) tLe"i>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]MV=@T^8#
Utility.log(header+" : "+con.getHeaderField(header)); A$XmO}+
else 0z=^_Fb
break; '645Fr[lg
} DzG$\%G2R}
} \kVi&X=q:
R\n*O@E v3
>R2o7~
public void splitterStop() gjex;h
{ 1A;f[Rze
bStop = true; S"Mm_<A$@
} y@u,Mv
y>_*}>2,O
Q%^!j_#
} .V\:)\<|
Tq!.M1{&
s_Gf7uC
/* ~ZZJ/Cu
**FileAccess.java hYU4%"X
*//文件访问(定位，写) Y|N.R(sAs&
package NetFox; w2o5+G=
import java.io.*; p& +w
Tn(c%ytN
zT"W(3
public class FileAccessI implements Serializable{ PvqG5-L~W
" )/febBS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y8%*S%yO
RandomAccessFile oSavedFile; 0N4+6k|
long nPos; m<| *
y?yWM8
@DA.$zn&
public FileAccessI() throws IOException =/L;}m)7
{ cuo'V*nWQ
this("",0); ":,J<|Oy
} ok<!/"RX$
a;[=bp
a<mM )[U
public FileAccessI(String sName,long nPos) throws IOException \XT~5N6
{ )0p7d:%mV
oSavedFile = new RandomAccessFile(sName,"rw"); dSw%Qv*y
this.nPos = nPos; QPT%CW61M
oSavedFile.seek(nPos); *HXx;:
} s2Hx?~
-|nHwSrCZ/
[nG@ 3n
public synchronized int write(byte[] b,int nStart,int nLen) oV Hh
{ \?rBtD(
int n = -1; &WAJ;7f
try{ 'r_NA!R
oSavedFile.write(b,nStart,nLen); ]9/{
n = nLen; 15tT%TC
} $g+q;Y~i0
catch(IOException e) ;Vh5nO
{ |}^BF%8V:
e.printStackTrace (); e:kd0)9
} Y<EdFzle
_vgFcE~E@
W2G@-`,
return n; B gB]M3Il
} z;d]=PT
-P7JaH/Q
25CO_
} F9 q9BH
F1UTj"<e
#>@~3kGg
/* &['cZ/bM
**SiteInfoBean.java @Ap~Wok
*/ [ bB
package NetFox; l/F'W}
B2DWSp-8*
K\a=bA}DG
public class SiteInfoBean { 8KhE`C9z
^J{tOxO=l
1pT-PO3=
private String sSiteURL; //Site's URL iF1E 5{dH
private String sFilePath; //Saved File's Path "<5su5]
private String sFileName; //Saved File's Name 60r4%>d
private int nSplitter; //Count of Splited Downloading File >qhoGg
zOzobd
^ H )nQ
public SiteInfoBean() re;^,
{//nSplitter的缺省值为5 HHU0Nku@ho
//default value of nSplitter is 5 Q1?09
this("","","",5); x]%'^7#v)
} KaGG4?=V
\6z_;
[[sfuJD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Rx>>0%e.
{ EA+}Rf6}
sSiteURL= sURL; slWO\AYiO
sFilePath = sPath; rfVHPMD0
sFileName = sName; P&0o~@`cL
this.nSplitter = nSpiltter; ;Q&|-`NK
Y4.t:Uzr
~xSAR;8
} ollk {N
sq~9 l|F
vOKWi:-U
public String getSSiteURL() Ug1n4X3FKn
{ lE@ V>%b
return sSiteURL; d}`Z| ex
} {j{H@rHuy
a.O pxd
p^uX{!
public void setSSiteURL(String value) !uwZ%Uxz
{ jR[3{ Reo
sSiteURL = value; :s5wFumD
} tUPdq0%t[
>|S&@<
(+^z9p7/!
public String getSFilePath() C%l+<wpXO
{ S[zX@3eZV
return sFilePath; 9< $n'g
} {+V]saYP
eXdE?j
i G%h-
public void setSFilePath(String value) Cj6+zJ
{ /\0rRT
sFilePath = value; WK<:(vu.
} 6pCQP c*A
tin5.N)"z
|)vC^=N{+
public String getSFileName() 2sryhS'(H
{ iE;D_m.>`O
return sFileName; !8V
} v.Y?<=E+<d
~;#OQ[
RMfKM! vE
public void setSFileName(String value) :4V8Iz 71
{ ".Q``d&X
sFileName = value; bI_T\Eft
} R rtr\a
yD-L:)@"
qlJzXq{|`
public int getNSplitter() 1K`7
{ C=6.~&(
return nSplitter; ..5rW0lr
} (&)PlIi7
8wXnc%
CC8)yO
public void setNSplitter(int nCount) g]V_)}
{ m@Vz42g~+
nSplitter = nCount; T|o ]8z
} ;;#_[Zl
} nH=8I~jp
R;]z/|8
mz'r<v2Tc
/* BM,]Wjfdj
**Utility.java %]m/fo4b
*/ \pVmSac,
package NetFox; z{N~AaY
-szSA
,L.*95,
public class Utility { P~H?[ ;
lI<Q=gd
nbMxQODk
public Utility() ; m]KKB
{ hN5?u:
m 3Y@p$i5
fQkfU;5
} t6+c"=P#
]"2;x
//线程睡眠 C2[* $ 1U
public static void sleep(int nSecond) XDtMFig
{ 1[g -f,
try{ @ gv^
Thread.sleep(nSecond); WE*L=_zDS
} YXi'^GU@
catch(Exception e) UBm L:Qv
{ +'ZJ]
e.printStackTrace (); !'jZ !NFO
} XjRk1~
} Biva{'[m
%lbDcEsf9
//日志 A%[BCY_
public static void log(String sMsg) s.#%hPX{
{ hp$/O4fD
System.err.println(sMsg); WEnI[JGe
} {PTB]D'
L2,.af6+
~v$1@DQ}
public static void log(int sMsg) >]!8f?,
{ cUH.^_a
System.err.println(sMsg); w1&\heSQ
} ZR,"w
} q9h3/uTv
aWCZ1F
M&v;#CV
/* C+m%_6<
**TestMethod.java zFba("E Z
*/ %2;Nj; J$
package NetFox; 2I|`j^
c;13V(Djy
]VkM)< +
public class TestMethod { dKk#j@[n"
(^@rr[.o7
d:X@zUR*)
public TestMethod() -91*VBrOd
{ ///xx/weblogic60b2_win.exe yd|roG/
try{ Km)VOX[ZZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L* 0$x
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); a7fFp9l!
SiteFileFetch fileFetch = new SiteFileFetch(bean); @,:6wKMc
fileFetch.start(); \`:nmFO(9
} AbExJ~JV\g
catch(Exception e){e.printStackTrace ();} @fc-[pv
\}n\cUy-
g!\H^d4
} P2!+ZJ&
28! ke
"M!]t,?S
public static void main(String[] args) f'oO/0lx
{ N8E
new TestMethod(); v:1DNR4
} 3-PqUJT$
} CiNOGSlDj
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