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)); =' &TqiIv"
} $O,IXA
for(int i=0;i<nEndPos.length-1;i++) 7%yP5c B
{ "tz`@3,5dN
nEndPos = nStartPos[i+1]; w%eEj.MI|i
} iJzW3%E
nEndPos[nEndPos.length-1] = nFileLength; c:,K{ZR
} !CLL{\F
} T^H`$;\
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:PP!v!vk
//启动子线程 %i@Jw
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~i=5NUE
for(int i=0;i<nStartPos.length;i++) X@Yl<9|i
{ lQ|i Ws
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \<x{U3q5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {%QWv%|
nStartPos,nEndPos,i); .2/W.z2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <v$yXA
fileSplitterFetch.start(); :2-!bLo}&
} 2$1D+(5;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V?4G~~F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V#\iO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g42f*~l
nEndPos = " + nFileLength); uEdeA'*^
// fileSplitterFetch[nPos.length-1].start(); /^b=| +Do
qQe23,x@5
@^^,VgW[
//等待子线程结束 tV9K5ON
//int count = 0; |1UJKJwX
//是否结束while循环 92g&,Wb
boolean breakWhile = false; kXW$[R
W)2ZeH*
nj7\vIR7
while(!bStop) )Qc>NF0
{ v Yw$m#@
write_nPos(); #&&
Utility.sleep(500); ;"+]bne~
breakWhile = true; @mu=7_$U
W(jP??up
])mYE }g
for(int i=0;i<nStartPos.length;i++) 5j#XNc)"
{ dPyZzMes=
if(!fileSplitterFetch.bDownOver) G$CI~0Se:
{ C%;J9(r
breakWhile = false; ' O d_:]
break; 6"|+\
} Fes/8*-
} HsAKz]Mq
if(breakWhile) k>!A~gfP~
break; A IsXu"
Q#sLIZ8=
u;=a=>05IR
//count++; _A=Pr_kN
//if(count>4) !KmSLr7xU
// siteStop(); g:fzf>oQ>p
} H(ds
=l1O9/\9
O"f|gc)GLz
System.err.println("文件下载结束！"); THz=_L6
} mY!&*nYn|
catch(Exception e){e.printStackTrace ();} ,B$m8wlI|
} L=<{tzTc
;p/$9b.0:
$qfNEAmDf\
//获得文件长度 PVX23y;
public long getFileSize() eC*-/$D
{ Gcd'-1
int nFileLength = -1; 2JLXDkZ
try{ uDsof?z
URL url = new URL(siteInfoBean.getSSiteURL()); lwp(Pq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8eZ^)9m
httpConnection.setRequestProperty("User-Agent","NetFox"); Bey|f/ <
1|3{.Ed
S'%!KGVe
int responseCode=httpConnection.getResponseCode(); p^?]xD(
if(responseCode>=400) jt4c*0z
{ uI+^8-HZ;
processErrorCode(responseCode); IjnO2X
return -2; //-2 represent access is error Qj(|uGqm3
} FAF+}
lb[\Lzdvmu
_.K<#S
String sHeader; i2m+s;
xGo,x+U*
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for(int i=1;;i++) [E4#|w
{ qn#f:xltu
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Nt P=m @
//Utility.log(in.readLine()); FOD_m&+
sHeader=httpConnection.getHeaderFieldKey(i); ?;?$\b=
if(sHeader!=null) [Z{0|NR
{ qo5WZ be
if(sHeader.equals("Content-Length")) J G3#(DVc;
{ ~6O<5@k
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,[|4{qli\
break; e$=0.GWT
} t+m ug
} -KFozwr5/
else A"R5Fd%6pc
break; XonI
} B3-;]6
} DXc3u^ L
catch(IOException e){e.printStackTrace ();} !%Qm{R
catch(Exception e){e.printStackTrace ();} &kNJs{
:/941?%M
eBxOa
Utility.log(nFileLength); 18kzR6(W
R[_UbN 28
8@- UvT&o
return nFileLength; 'n0u6hCSb
} QzX|c&&>u2
y759S)U>>p
Cz]NSG5
//保存下载信息（文件指针位置） )%=oJ!)
private void write_nPos() >r~!'Pd!
{ gQ~X;'
try{ :;u?TFCRx
output = new DataOutputStream(new FileOutputStream(tmpFile)); mQy!*0y
output.writeInt(nStartPos.length); Y> f 6
for(int i=0;i<nStartPos.length;i++) ={gfx;
{ L>1i~c&V
// output.writeLong(nPos); Zh,{e/j
output.writeLong(fileSplitterFetch.nStartPos); |*-&x:p7O
output.writeLong(fileSplitterFetch.nEndPos); Kitx%P`i
} @h";gN
output.close(); Zm~oV?6
} 2/v9
catch(IOException e){e.printStackTrace ();} mq*Efb)!
catch(Exception e){e.printStackTrace ();} FCMV1,
} +4*jO5EZ
+YK/^;Th
";$rcg"%X
//读取保存的下载信息（文件指针位置） qZ|>{^a*
private void read_nPos() @ob4y
{ (zL(
try{ Zcg@]Sx(I
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); j65qIw_Z
int nCount = input.readInt(); j`pX2S
nStartPos = new long[nCount]; -OPJB:7Z
nEndPos = new long[nCount]; gS$?#!f
for(int i=0;i<nStartPos.length;i++) N#"(
{ 2%*mL98WK
nStartPos = input.readLong(); YqSkz|o}m
nEndPos = input.readLong(); Y6r<+#V
} x=~$ik++
input.close(); '#p2v'A
} ;u "BCW
catch(IOException e){e.printStackTrace ();} I#U"DwM
catch(Exception e){e.printStackTrace ();} E ) iEWc
} |SfmQ;
jX8,y
pa)2TL/@
private void processErrorCode(int nErrorCode) z),@YJU"z
{ 8C(@a[V
System.err.println("Error Code : " + nErrorCode); !H[K"7w
} "hi)p9 _cR
HE0@`(mCpa
sp'f>F2]
//停止文件下载 d iGkwKj
public void siteStop() 236,o {9e
{ 8%W(",nd
bStop = true; ! >l)*jN8
for(int i=0;i<nStartPos.length;i++) V$';B=M
fileSplitterFetch.splitterStop(); ir/-zp_
MX\v2["FoV
zv}3Sl@
} P>s3Rh3:
} F vt5vQ
//负责部分文件的抓取 ;+-M+9"?O
**FileSplitterFetch.java y2:~_MD
*/ "{F e
package NetFox; a8wQ,
m^M sp:T,
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import java.io.*; />,KWHR|:
import java.net.*; 12JmSvD
x%d\}%]
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public class FileSplitterFetch extends Thread { s}5,<|DL
ub,GF?9
SZ'2/#R>
String sURL; //File URL WQ>y;fi5/{
long nStartPos; //File Snippet Start Position U3UDA
long nEndPos; //File Snippet End Position \2Atm,#4
int nThreadID; //Thread's ID v@^P4cu;
boolean bDownOver = false; //Downing is over ?f\ ~:Gm/
boolean bStop = false; //Stop identical k9Xv@v
FileAccessI fileAccessI = null; //File Access interface F&= X/
K.T.?ug;:
GjD^\d/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i SD?y#
{ )J<VDO:_YA
this.sURL = sURL; Pv3rDQ/Yt|
this.nStartPos = nStart; DN%b!K:
this.nEndPos = nEnd; 8pZGu8
nThreadID = id; lUJ~_`D
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u{+z?N
} wYLi4jYm
4ZAnq{nR4
uKL4cr@
public void run() P^Tk4_,0
{ j{?ogFfi
while(nStartPos < nEndPos && !bStop) vl,Ff9
{ 3{*nG'@Mal
Q eZg l!
S_ELV#X
try{ JsZLBq*lP
URL url = new URL(sURL); 9\J.AAk~/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <<5x"W(,
httpConnection.setRequestProperty("User-Agent","NetFox"); gf\F%VmSN
String sProperty = "bytes="+nStartPos+"-"; FT$Z8
httpConnection.setRequestProperty("RANGE",sProperty); I"5VkeIx
Utility.log(sProperty); A0f98?j^
{dF_=`.
lCAD $Ia~
InputStream input = httpConnection.getInputStream(); ~p* \|YC
//logResponseHead(httpConnection); s=BJ7iU_68
Y:-O/X
t<DZW#
byte[] b = new byte[1024]; (- QvlpZ
int nRead; 31> $;"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #vs=yR/tn{
{ dPmtU{E<M
nStartPos += fileAccessI.write(b,0,nRead); LeTOVgjA|
//if(nThreadID == 1) )U5Ba^"fI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8EBy5X}US
} OoqA`%
u>y/<9]q8
1>IA9]D7
Utility.log("Thread " + nThreadID + " is over!"); z3mo2e
bDownOver = true; w$1B|7tX;2
//nPos = fileAccessI.write (b,0,nRead); Ak'=/`+p
} EjDr
catch(Exception e){e.printStackTrace ();} 5%K(tRc|
} (ibj~g?U,
} GJo`9
oT}-i [=}
:% m56
//打印回应的头信息 *< ?~
public void logResponseHead(HttpURLConnection con) y|Vwy4tK9
{ PC55A1(T
for(int i=1;;i++) 'irHpN6n
{ nKu)j3o`
String header=con.getHeaderFieldKey(i); nSR<(-j!
if(header!=null) 1 LUvs~Qu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @5:#J!
Utility.log(header+" : "+con.getHeaderField(header)); t8_i[Hw6D
else )~LqBh
break; k,0lA#>
} L_{gM`UFc
} g* DBW,
3@8Zy:[8<
kl[Jt)"4@
public void splitterStop() oa q!<lI
{ dm`:']?
bStop = true; l37) Q
} 5kdh!qy[$,
I\WBPI
tuIQiWHbM
} <#>{7" }
%Xjg/5G-
Jnl#d0) -
/* U%u%_{-
**FileAccess.java Fsi;[be$A
*//文件访问(定位，写) D wtvtglqV
package NetFox; ^"!)p2=
import java.io.*; ;9"6g=q
Cj1nll8c
Y'eE({)<K
public class FileAccessI implements Serializable{ =}wqo6Bn|
\VAm4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ee\xj$,
RandomAccessFile oSavedFile; qx2M"uFJ
long nPos; R Y ";SfYb
8;GuJP\
MG(qQ#;j/
public FileAccessI() throws IOException cj@ar^=`K
{ /&!4oBna
this("",0); "R %3v.Z
} o%_Hmd;_'
gBd@4{y6C.
dO!5` ]
public FileAccessI(String sName,long nPos) throws IOException S<Od`I
{ 4KnrQ-D
oSavedFile = new RandomAccessFile(sName,"rw"); CEl9/"0s6
this.nPos = nPos; G/y;o3/[Z
oSavedFile.seek(nPos); E;-*LT&{
} s^zX9IVnp
3Xl!Z^W
+V;@)-
public synchronized int write(byte[] b,int nStart,int nLen) }+dDGFk
{ *9)yN[w
int n = -1; 6u[ B}%l
try{ 07#e{
oSavedFile.write(b,nStart,nLen); ds "N*\.
n = nLen; 9D,/SZ-v
} rJw Ws
catch(IOException e) U])$#/ v
{ vHM,_I{
e.printStackTrace (); r"bV{v
} 4ztU) 1
\Jm^XXgS
>})W5Y+
return n; z 8y.@<6
} y41,T&ja
(Y:?qy
AZf$XHP2
} +XoY@|Djd
Un^3%=;
qi=v}bp&
/* eYD-8*
**SiteInfoBean.java 6O| rI>D
*/ CA]u3bf~
package NetFox; 2kW*Z7@D
GB8>R
Y@2v/O,\
public class SiteInfoBean { ;Yu|LaI\<m
,ocAB;K
"fOxS\er
private String sSiteURL; //Site's URL 1^AG/w
private String sFilePath; //Saved File's Path DM=`hyf(v
private String sFileName; //Saved File's Name (Q[(]dfc
private int nSplitter; //Count of Splited Downloading File A?4s+A@Eg
,}a'h4C
&b9bb{y_$K
public SiteInfoBean() x't@Mc
{//nSplitter的缺省值为5 ?AYb@&%
//default value of nSplitter is 5 B'8T+qvA
this("","","",5); |DkK7gw
} M&J$9X
'h3yxf}\
?~=5x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) K_o[m!:jU
{ u5rHQA0%
sSiteURL= sURL; YlJ_$Q[
sFilePath = sPath; Ngw/H)<c
sFileName = sName; ?cKe~Q?3
this.nSplitter = nSpiltter; m,^UD{
X-j3=8wPM
@@"abhT
} JL!:`#\
0;Z] vl/|
`L7Cf&W\l8
public String getSSiteURL() |{9&!=/qf
{ -s&7zqW
return sSiteURL; ^k5#{?I
} fx*Q,}t
O\q-Ai
Tu&W7aoX5
public void setSSiteURL(String value) ufvjW]
{ !eA6Ejf
sSiteURL = value; nXAGwU8a
} bmI6OIWl
bu,xIT^
a+,zXJQYq
public String getSFilePath() PaZd^0'!Z
{ 5Mz6/&`
return sFilePath; L17{W4
} 8T}Dn\f
h)h%y)1
4MPR
public void setSFilePath(String value) k\Z@B!VAq
{ Rgb&EnVW
sFilePath = value; =i:,")W7=
} {+jO/ZQu5
Q3rLCg,;
}.N~jx0R
public String getSFileName() c_Jcy
{ 1{.5X8y1x
return sFileName; i#:M2&twE
} <|1Khygv
L|Bjw3K&D
",P?jgs^g5
public void setSFileName(String value) H?wf%0
{ EqF>=5*
sFileName = value; h.4FY<
} `i)Pf WdBN
>6Ody<JPHP
=?[:Nj636
public int getNSplitter() (CrP6]=
{ BY>]6SrP
return nSplitter; hUe\sv!x?
} L3Ivm:
vY);7
pMV?vH
public void setNSplitter(int nCount) *X8Pa;x
{ +c' n,O~3
nSplitter = nCount; !112u#V
} I|. <
} Xh@;4n
a^7QHYJ6
b]g#mQ
/* ccwz:7r
**Utility.java g4&f2D5
*/ 6 jU?~
package NetFox; 8f>v[SQ"
9gac7(2`)
He1~27+99
public class Utility { F0ylJ /E
hq?F81
ZwMd 22
public Utility() 3u/ GrsF
{ 2?kVbF
D*t[5,~j
58t~? 2E
} h(p cGE
O:Wd ,3_
//线程睡眠 #@m6ag.
public static void sleep(int nSecond) J+l#!gk$!
{ &Xh=bM'/%m
try{ uTNy{RBD+
Thread.sleep(nSecond); uoTc c|Kc
} KN'twPFq
catch(Exception e) \0.!al0
{ 't+'rG6x
e.printStackTrace (); =Y*zF>#lP
} 5h6-aQU[
} \?[m%$A
i4lB]k
//日志 &n]]OPo
public static void log(String sMsg) <.:mp1,8V
{ <vd}oiB@
System.err.println(sMsg); 85BB{T;
} }c=YiH,o
EpK7VW
m O"Rq5
public static void log(int sMsg) sNZOm$
{ R0e!b+MZ.
System.err.println(sMsg); C:z7R" yj
} IwR=@Ne8
} B$MHn?
o.wXaS8
z`sW5K(A
/* f('##pND@
**TestMethod.java BO0Y#fs
*/ ~^>g<YR[
package NetFox; (dP9`Na]
2XyC;RWJ%
DI[
public class TestMethod { !eP0b~$/^J
_ygdv\^Tet
DTl&V|h$
public TestMethod() BirnCfj/2
{ ///xx/weblogic60b2_win.exe .&.L@CRH
try{ I5E+=.T*ar
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :=\`P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); h<i.Z7F;tj
SiteFileFetch fileFetch = new SiteFileFetch(bean); G0(A~Q"
fileFetch.start(); uTrQ<|}#
} Q}uh`?t
catch(Exception e){e.printStackTrace ();} 0yxwsBLy
Yu:($//w
o(D6
} M $zt;7P|
O@>{%u
at(gem
public static void main(String[] args) (I;lE*>
{ A_+*b [P
new TestMethod(); R)Dh;XA
} o<rbC < U
} !L)yI#i4C
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