http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); rpvm].4
} eu~;G H
for(int i=0;i<nEndPos.length-1;i++) 4P.ry|2
{ ixp%aRRP
nEndPos = nStartPos[i+1]; /w|YNDA]j
} @{bf]Oc
nEndPos[nEndPos.length-1] = nFileLength; hX^XtIC=
} ka(xU#;
} yO !*pC
x@/!H<y
N7NK1<vw2
//启动子线程 vt1!|2{ h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $h2h&6mH
for(int i=0;i<nStartPos.length;i++) ;gF"o5/Q
{ zpY8w#b
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I?1^\s#L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5EU3BVu&u
nStartPos,nEndPos,i); wBr0s*1I
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _H-Lt{k
fileSplitterFetch.start(); 8.vD]hO
} u+-}|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dfNNCPu]+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #e=[W))
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F:\CDM=lS
nEndPos = " + nFileLength); Ts.61Rx
// fileSplitterFetch[nPos.length-1].start(); /u?^s "C/
RxAZ<8T_
Baq&>]
//等待子线程结束 VlKWWQj
//int count = 0; # TvY*D,
//是否结束while循环 &n['#7 <(!
boolean breakWhile = false; 1>n@`M8}
ZM\Z2L]n
Mq-;sPsFP
while(!bStop) -(Yq$5Zc&
{ d}Q;CF3m:
write_nPos(); At"@`1n_u'
Utility.sleep(500); 7%C6gU!r
breakWhile = true; zh7NXTzyf
yAaMYF@
`Os@/S
for(int i=0;i<nStartPos.length;i++) "Ln)v
{ tX)^$3A
if(!fileSplitterFetch.bDownOver) : xW.(^(d
{ iOw'NxmY
breakWhile = false; ,|D<De\v&
break; "1Vuf<?C
} y4+Km*am,W
} I t",WFE.
if(breakWhile) H}`}qu #~V
break; ?m0|>[j
%R."
=5J}CPKbZI
//count++; |pA3ZWm
//if(count>4) kyMWO*>|
// siteStop(); eX>x +]l6
} 2{(_{9<>z
4~4D1
&Yb!j
System.err.println("文件下载结束！"); )17CG*K1
} F@UbUm2o
catch(Exception e){e.printStackTrace ();} D&#wn.0|E
} 3,t3\`=
^z)p@sk#
D5^wT>3>
//获得文件长度 p%[/ _ -7
public long getFileSize() kIrb;bZ+l
{ ?cF`T/z]"
int nFileLength = -1; b"iPuN!p
try{ NSI$uS6
URL url = new URL(siteInfoBean.getSSiteURL()); l$ ^LY)i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Qq+$ea?>
httpConnection.setRequestProperty("User-Agent","NetFox"); Bq@_/*'*Y
c&X2k\
,v,#f .
int responseCode=httpConnection.getResponseCode(); =#0f4z
if(responseCode>=400) nHyqfd<V>
{ qjDt6B^RO
processErrorCode(responseCode); 9X/]O<i,Es
return -2; //-2 represent access is error e*)*__$O
} 9?]69O
O3 NI
zl $mt'\y
String sHeader; []OmztB
^pwT8Bp
7bSj[kuN
for(int i=1;;i++) 8n??/VDRl
{ l]R=I2t
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XSHK7vpMf
//Utility.log(in.readLine()); =hY9lxW
sHeader=httpConnection.getHeaderFieldKey(i); TAB'oLNp
if(sHeader!=null) !{q_Q !
{ 4g+Dp&U
if(sHeader.equals("Content-Length")) N1iP!m9Q
{ Y#[xX2z9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Zz/ z7~{
break; {:]u 6l
} 0uL*-/|
} WA((>Daf]
else X{Ij30Bmv
break; 8Wba Hw_
} zt;aB>jz#
} 3!M|Sf<s
catch(IOException e){e.printStackTrace ();} o3W@)|>
catch(Exception e){e.printStackTrace ();} 'D'H)J
Z\r?>2
CT?4A1[aD
Utility.log(nFileLength); ^ 6b27_=
"% l``
%/oeV;D
return nFileLength; =&Z#QD"vl
} W#&BU-|2
s}qtM.^W
x3:d/>b
//保存下载信息（文件指针位置） )LAG$Cn
private void write_nPos() #f@}$@
{ +;T\:'CU
try{ _1G;!eO
output = new DataOutputStream(new FileOutputStream(tmpFile)); 'i<%kL@
output.writeInt(nStartPos.length); %6\L^RP
for(int i=0;i<nStartPos.length;i++) osn ,kD*
{ +,]_TxL|C
// output.writeLong(nPos); bgeJVI
output.writeLong(fileSplitterFetch.nStartPos); {8 #
output.writeLong(fileSplitterFetch.nEndPos); CC)Mws+2
} 3/y"kl:<-
output.close(); ; GEr8_7
} .Zc:$"gDu
catch(IOException e){e.printStackTrace ();} &D91bT+L
catch(Exception e){e.printStackTrace ();} !5 ?<QKOe
} </pt($
?$MO!
]?T,J+S
//读取保存的下载信息（文件指针位置） MU4BAN
private void read_nPos() P~84#5R1
{ _\<TjGtG
try{ T|p%4hH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); LJA uTg
int nCount = input.readInt(); /[5\T2GI
nStartPos = new long[nCount]; a4XK.[O
nEndPos = new long[nCount]; X4L@|"ZI
for(int i=0;i<nStartPos.length;i++) Wcbm,O4u
{ ]c1#_MW
nStartPos = input.readLong(); sf O{.#5<
nEndPos = input.readLong(); !D!"ftOm
} /.(~=6o5
input.close(); Wj8WT)cB
} fZ(k"*\MZ
catch(IOException e){e.printStackTrace ();} e5D\m g)
catch(Exception e){e.printStackTrace ();} Bjh8uW G
} 8@ S@^C*F
%XQJ!sC`
~R\ $Z
private void processErrorCode(int nErrorCode) R[kF(C&
{ _C=01 %/
System.err.println("Error Code : " + nErrorCode); 21my9Ui]
} e:K'e2
]f5vk
)=cJW(nfP
//停止文件下载 Y5y7ONcn
public void siteStop() sX]gL
{ qoZe<jW (
bStop = true; d6ifJ
for(int i=0;i<nStartPos.length;i++) h*Mt{A&'.&
fileSplitterFetch.splitterStop(); a5(9~.9
>}/T&S
MShcZtN
} AF,;3G
} '$VP\Gj.
//负责部分文件的抓取 G *<g%"
**FileSplitterFetch.java iVo-z#
*/ 'UTMEN&
package NetFox; 3T>6Q#W5eO
NZlCn:"
p}JGx^X~
import java.io.*; >p`i6_P0P/
import java.net.*; c[;A$P= 8.
E>:#{%
#GfM^sK
public class FileSplitterFetch extends Thread { =iB$4d2
hu7oJ H
9?^0pR p
String sURL; //File URL 1(Z+n,Hh
long nStartPos; //File Snippet Start Position z@~mu
long nEndPos; //File Snippet End Position lv~ga2>z
int nThreadID; //Thread's ID zn0%%x+!g
boolean bDownOver = false; //Downing is over ~@e=+Z
boolean bStop = false; //Stop identical r9<#R=r)}J
FileAccessI fileAccessI = null; //File Access interface /XNC^!z6Js
?kRx;S+
n0t+xvNDF_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException N7GZ'-t^Er
{ YRv}w3yQ
this.sURL = sURL; Pa=xc>m^
this.nStartPos = nStart; A<(Fn_&W
this.nEndPos = nEnd; ^)'D eP/
nThreadID = id; 4^9qs%&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 gc b8eB,
} -Vs;4-B{9
|h&okR+_,
G @]n(\7Y
public void run() ,#9i=gp
{ 1\AcceJ|(w
while(nStartPos < nEndPos && !bStop) Dc 84^>l
{ ? :A%$T
T hVq5
i?V:+0#q\]
try{ b/tcD r
URL url = new URL(sURL); 3ly]DTbz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {$7vd
httpConnection.setRequestProperty("User-Agent","NetFox"); .3wx}!:*|
String sProperty = "bytes="+nStartPos+"-"; K.}jyhKIKi
httpConnection.setRequestProperty("RANGE",sProperty); +x?8\
Utility.log(sProperty); LaL{ ^wP
IU"n`HS
Cd_H<8__
InputStream input = httpConnection.getInputStream(); ]<9o>#3
//logResponseHead(httpConnection); cnDF`7xrT
]6MXG%
/N")uuv
byte[] b = new byte[1024]; V<U9Pj^?^
int nRead; dV^ck+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k`\L-*:Ji
{ a4]=4[(iu>
nStartPos += fileAccessI.write(b,0,nRead); > lI2r}
//if(nThreadID == 1) gEmsPk,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "b"|ay
} M(ie1Ju
Wi*HLP!lNC
`2j"Z.=
Utility.log("Thread " + nThreadID + " is over!"); sD6vHX%
bDownOver = true; YdYaLTz
//nPos = fileAccessI.write (b,0,nRead); mAe)Hy %
} yATXN>]l
catch(Exception e){e.printStackTrace ();} (%fSJCBl[P
} I@1VX5
} kPSi6ci
]XWtw21I1
Pb7-pu5X
//打印回应的头信息 ("=B,%F_
public void logResponseHead(HttpURLConnection con) c=Zurqj
{ -(E-yCu
for(int i=1;;i++) "&\]1A}Z-x
{ h0l_9uI
String header=con.getHeaderFieldKey(i); ciN*gwI)
if(header!=null) OjK+`D_C
//responseHeaders.put(header,httpConnection.getHeaderField(header)); '=UsN_@
Utility.log(header+" : "+con.getHeaderField(header)); NH,4>mV$!
else j^Ln\N]^
break; %'9&JsO
} C1-Jj_XQ.
} f=>iiv
4@@gC&:Y
CSr2\ogT
public void splitterStop() %,udZyO3uR
{ ~tB9kLFG
bStop = true; <7j"CcJzZ
} ,(kaC.Em
Z}>+!Z
2K2*UC`f
} ro^T L
Fz]!2rt
N&W7g#F
/* ::Pf\Lb>
**FileAccess.java =CL h<&
*//文件访问(定位，写) A$]#f
package NetFox; uJJP<mDgA
import java.io.*; J 77*Ue^
v3]~*\!5
tsf!Q
public class FileAccessI implements Serializable{ z2SR/[I?
w6[$vib'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SXmh@a"*\
RandomAccessFile oSavedFile; wM#q [m;
long nPos; 62>/0_m5
83:qIfF
!)uXCg9U
public FileAccessI() throws IOException z9^_5la#
{ 2spK#0n.HV
this("",0); jHc/ EZB
} ~VJP:Y{[
13I~
=L}$#Y8?
public FileAccessI(String sName,long nPos) throws IOException Ijs=4f
{ [,mcvO;
oSavedFile = new RandomAccessFile(sName,"rw"); v0|"[qGb
this.nPos = nPos; \J^xpR_0u
oSavedFile.seek(nPos); KnYHjJa
} Q37zBC0
}/Y)^
A;Uw b
public synchronized int write(byte[] b,int nStart,int nLen) 0"=}d y
{ Rj,M|9Y)o
int n = -1; l,1.6
try{ iTeFy-Ct
oSavedFile.write(b,nStart,nLen); 7R".$ p
n = nLen; C,3yu,'
} u9dL-Nr`
catch(IOException e) JPS<e*5
{ \ffU15@N
e.printStackTrace (); |-VbJd
} *wJ'Z4_5F
ij1g2^],4
|}K7Q
return n; `H\NJ,
} \fD[Ej
~7&O[
y1hJVYE2
} .(zZTyZr
j_~lc,+m
'#x<Fo~hT
/* Q$DF3[NC
**SiteInfoBean.java k3t2{=&'&x
*/ [0hZg
package NetFox; 7$I *ju_
.AZ+|?d
cOEzS
public class SiteInfoBean { FI(M 1iJ
U>_#,j
9:6d,^X
private String sSiteURL; //Site's URL *gXm&/2*
private String sFilePath; //Saved File's Path 7S9Q{
private String sFileName; //Saved File's Name 1oIu~f{`
private int nSplitter; //Count of Splited Downloading File wenJ(0L|
%uhhQ<zs%
RlTVx:
public SiteInfoBean() )ur&Mnmm
{//nSplitter的缺省值为5 X+XbIbUuL
//default value of nSplitter is 5 nzORG
this("","","",5); ecy41y'~:
} &,@wLy^T
Mt`XHXTp
t9 m],aH
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )BLoj:gYn
{ s *1%I$=@
sSiteURL= sURL; YJ^TO\4WM
sFilePath = sPath; \:wLUGFl5
sFileName = sName; 4Vi&Y')f
this.nSplitter = nSpiltter; b`sph%&
Dbo.N`
Gk5SG_o
} 8RR6f98FF
4\yKd8I
+bK.{1
public String getSSiteURL() F /:2+
{ vmXY}Ul
return sSiteURL; JP<Z3 A2q
} 9#@CmiIhy
v{2Vg
+C !A@
public void setSSiteURL(String value) sIJ37;ZA
{ 8h2!8'
sSiteURL = value; "ci<W_lx
} +iPS=?S
C&'Y@GE5
N]sX r
public String getSFilePath() v+*l|!v
{ gZs8BKO
return sFilePath; Up$vBE8i]
} :I}_
O({-lI
%j=,c{`Q
public void setSFilePath(String value) (IR'~:W
{ IczEddt@'
sFilePath = value; rkl/5z??
} jjm-%W@
2aN
-~h2^Oez
public String getSFileName() UmU=3et<Wj
{ 7c6-S@L
return sFileName; )N2yhdcqI
} g5to0
mHox
<_H0Q_/(
public void setSFileName(String value) xTM&SVNbL_
{ :OBggb#?!
sFileName = value; ? F fw'O
} 0p$?-81BJ
@11voD
nZN]Q9
public int getNSplitter() >|7&hj$
{ 4#=!VK8ZH
return nSplitter; @Cm"lv.hz
} *(d^k;
$zz=>BOk
~%Yh`c EP
public void setNSplitter(int nCount) Ye!=
{ yZFvpw|g
nSplitter = nCount; '7'cKp
} 3g|O2>*?
} M7,|+W/RK
uD:O[H-x
}.zgVLL
/* NM~e
**Utility.java nhXa&Nro
*/ 3[aJ=5
package NetFox; dt3Vy*zL
0#*\o1r\p
[AX).b
public class Utility { 9f,HjRP
b<.+WkO
"TjR]jnV(
public Utility() R?|_`@@A
{ 7P|(j<JX6'
*bRH,u
}>frK#S
} gi;V~>kh
aeBth{
//线程睡眠 vlj|[joXw
public static void sleep(int nSecond) sCRBKCR?
{ H V
try{ Tu/JhP/g,`
Thread.sleep(nSecond); P<4jY?.
} s.GhquFCrU
catch(Exception e) `XWxC:j3%
{ GF/p|I D
e.printStackTrace (); {8B\-LUR
} 5E!|-xD
} E!Fy2h>[Z
H8-,gV
//日志 IG9Q~7@
public static void log(String sMsg) ([9h.M6v
{ x6)
System.err.println(sMsg); 10}Zoq|)n
} WVNQ}KY
)E[5lD61
)7i?8XiSZF
public static void log(int sMsg) lP9I\Ge&
{ nO|S+S_9
System.err.println(sMsg); xwRnrWd^6
} ~hxB Pn."
} o"]eAQ
yZ!Eu#81
@`_j't,
/* %cm5Z^B1"
**TestMethod.java 6=@n b3D%
*/ _E30t( _.
package NetFox; ?xf;#J+{8
.e"jnP~
Zgg7pL)#c
public class TestMethod { {!/y@/NK2
TAAsV#l
G1nW{vce
public TestMethod() 7K;dVB
{ ///xx/weblogic60b2_win.exe v =?V{"wk!
try{ hx2C<;s4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); yCkm|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `Eu(r]:W
SiteFileFetch fileFetch = new SiteFileFetch(bean); KqSa"76R
fileFetch.start(); {tT`It
} NuooA
catch(Exception e){e.printStackTrace ();} O)5PUyC:H
Fd\XDc[g
r2](~&i2
} '0O[dN
Z*TW;h0ZQ3
Zn/9BO5
public static void main(String[] args) RYV6hp)|
{ /-hF<oNQ
new TestMethod(); "{Bek<
} |ber:1
} 3'"M31iA
点击下载更多相关资料