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)); G{s ,Y^
} >,9t<p=Q
for(int i=0;i<nEndPos.length-1;i++) z,NHH):~
{ _\1(7?0D
nEndPos = nStartPos[i+1]; mki=.l$O
} 5jV]{ZV#
nEndPos[nEndPos.length-1] = nFileLength; w"Z>F]YZ
} |UBJu `%
} LZ@^ A]U
h&Sl8$jVp
_}\&;
//启动子线程 vdo[qk\C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >0m-S :lk
for(int i=0;i<nStartPos.length;i++) !7w-?1?D
{ LRmO6>y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G(4k#jB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <6`,)(dj
nStartPos,nEndPos,i); vXf#gX!Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eFx*lYjA
fileSplitterFetch.start(); E8503
} #2dmki"~(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vD*KJ3(c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $X{& KLM[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nQgn^z#
nEndPos = " + nFileLength); Ne4A
// fileSplitterFetch[nPos.length-1].start(); 7Jqp2\
XYn$yR\dj
k82'gJ;MC=
//等待子线程结束 3)7'dM
//int count = 0; 'dg OE
//是否结束while循环 C/cyqxVl}
boolean breakWhile = false; c=K M[s.
4Pt0^;H&jn
D`gY6wX
while(!bStop) :4A^~+J
{ qR1ez-#K
write_nPos(); q}8R>`Z{
Utility.sleep(500); ~!uK;hI
breakWhile = true; fpqKa r
D/)xe:
_Ih~'Y Fd
for(int i=0;i<nStartPos.length;i++) abK/!m[q
{ B^OhL!*tI
if(!fileSplitterFetch.bDownOver) fGxa~Unx
{ WT0U)x( m5
breakWhile = false; b :+ X3
break; F |GWYw'%
} `aUA_"f
} i^W\YLE
if(breakWhile) .d*vfE$
break; 2{qoWys8[
aJfW75C
-V+fQGZe
//count++; BvYJ!Vj
//if(count>4) "44X'G8N
// siteStop(); \t(/I=E8/
} R{WG>c
yK{~
nqV7Db~
System.err.println("文件下载结束！"); 7+z%O3k'I
} rzex"}/ly
catch(Exception e){e.printStackTrace ();} Axcm~!uf
} ;\H2U.
`yf#(YP
@hCGV'4
//获得文件长度 YS/DIH{9e
public long getFileSize() [k.<x'#
{ Hu;#uAnxQ
int nFileLength = -1; :JOF!Q
try{ _E1:3N|
URL url = new URL(siteInfoBean.getSSiteURL()); BeVQ[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r..Rh9v/=E
httpConnection.setRequestProperty("User-Agent","NetFox"); eQNYfWR
*l5/q\D
GB{%4)%6
int responseCode=httpConnection.getResponseCode(); :_vf1>[
if(responseCode>=400) 5` Q#2
{ X09&S4
processErrorCode(responseCode); =XqmFr;h
return -2; //-2 represent access is error 76hi@7a
} l.&6|
pV1~REk$&
K)&AR*Tc
String sHeader; T]0qd^\4w
RCsd
<Nkj)`%5iK
for(int i=1;;i++) zEa3a
{ -`A6K!W&~p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &6!x;RB
//Utility.log(in.readLine()); -l^u1z
sHeader=httpConnection.getHeaderFieldKey(i); oo<,hOv
if(sHeader!=null) Bl(we/r
{ w%`7,du|
if(sHeader.equals("Content-Length")) ?a(ApD\
{ 4D0"Y#&G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9CxU:;3
break; @UX'(W
} ;Q\Duj
} $2\OBc=
else `rQA9;Tn2
break; 2jaR_``=:
} V:yia^1
} \]GBd~i<
catch(IOException e){e.printStackTrace ();} j]YS(Y@AY
catch(Exception e){e.printStackTrace ();} >+&524xc
eAPGy-
JH5ckgdZ
Utility.log(nFileLength); <AzvVSA,
MsfY|(/m
@/7tN3O
return nFileLength; eR=P
} Hh,q)(Wo
]^E<e!z={$
g&X$)V4C
//保存下载信息（文件指针位置） YGNO]Q~A
private void write_nPos() 4OC^IS
{ tpU[KR[-
try{ *i&ks>4N
output = new DataOutputStream(new FileOutputStream(tmpFile)); bF<FX_}!s!
output.writeInt(nStartPos.length); 8|HuxE
for(int i=0;i<nStartPos.length;i++) }H\wed]F/
{ M2{{B^*$6
// output.writeLong(nPos); ' FF@I^O
output.writeLong(fileSplitterFetch.nStartPos); REli`"bR
output.writeLong(fileSplitterFetch.nEndPos); yd'>Mw
} 5hg:@i',
output.close(); iJT_*,P^
} )Z,O*u*
catch(IOException e){e.printStackTrace ();} g>cp;co9g
catch(Exception e){e.printStackTrace ();} =:uK$>[
} X=8y$Yy
n~@;[=o?5
0p)#!$
//读取保存的下载信息（文件指针位置） $@s&qi_&R
private void read_nPos() I ze+](
{ ]-&A)M6
try{ V+(1U|@~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !0i
int nCount = input.readInt(); $TGE
nStartPos = new long[nCount]; <Y9%oJn%
nEndPos = new long[nCount]; A_i=hj2f
for(int i=0;i<nStartPos.length;i++) M2l0x @|
{ iP)`yB5`
nStartPos = input.readLong(); il|e5TD^
nEndPos = input.readLong(); )w4i0Xw^C:
} 'S;INs2|->
input.close(); \QGh@AQp"
} Y{ijSOl3
catch(IOException e){e.printStackTrace ();} 49W@?:b
catch(Exception e){e.printStackTrace ();} yb\T<*
} sIJl9
C8W#$a
2<q>]G-nN
private void processErrorCode(int nErrorCode) =^\yE"a
{ 3"FvYv{
System.err.println("Error Code : " + nErrorCode); }>]V_}h
} P%2aOsD0
8iA[w-Pv
6#hDj_(,
//停止文件下载 IOhJL'r
public void siteStop() UuPXo66F]
{ L7VDZCV
bStop = true; $KHw=<:)/
for(int i=0;i<nStartPos.length;i++) 7@oM?r7td
fileSplitterFetch.splitterStop(); >"5f B
W|'7)ph
@G,pM: t
} ^hiIMqY_{`
} @cRR
//负责部分文件的抓取 <NKmLAfX
**FileSplitterFetch.java D`d*bNR
*/ A#k(0e!O
package NetFox; !?)ky `S3
VokIc&!Uz
B>C+qj@
import java.io.*; :8h\x
import java.net.*; -Y>,\VEK
v]{F.N
vxE#6
public class FileSplitterFetch extends Thread { `xv2,Z9<
UI2TW)^2
/oL& <e
String sURL; //File URL pW5ch"HE
long nStartPos; //File Snippet Start Position #!?jxfsFa
long nEndPos; //File Snippet End Position H?oBax:
int nThreadID; //Thread's ID B!+rO~
boolean bDownOver = false; //Downing is over ad)jw:n
boolean bStop = false; //Stop identical /]pJ(FFC
FileAccessI fileAccessI = null; //File Access interface xbqFek$/r
yzyBr1s
N> 7sG(!'"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `)y<X#[8
{ RISDjU3
this.sURL = sURL; L!;"73,&(8
this.nStartPos = nStart; Lh@0|k
this.nEndPos = nEnd; f |%II,!3
nThreadID = id; $|"Y|3&X
fileAccessI = new FileAccessI(sName,nStartPos);//定位 H2kib4^i
} `D-P}hDm!
2JdzeJb
S@Iza9\|@
public void run() A>\5fO
{ eR3v=Q
while(nStartPos < nEndPos && !bStop) kI?+\k\V`
{ u*}ltR~/
YuXCRw9p;
<?Ln`,Duk
try{ pl}nbY
URL url = new URL(sURL); C]EkVcKFA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *c<6 Er>s
httpConnection.setRequestProperty("User-Agent","NetFox"); OI^??joQ
String sProperty = "bytes="+nStartPos+"-"; o%yfR.M6$
httpConnection.setRequestProperty("RANGE",sProperty); !),eEy
Utility.log(sProperty); v*";A
;NMv>1fI
!MXn&&e1
InputStream input = httpConnection.getInputStream(); LUs)"ZAi|
//logResponseHead(httpConnection); /9pN.E
=fRC$
ObPXVqG"?
byte[] b = new byte[1024]; &=^YN"=Z
int nRead; pKtN$Fd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _jb'HP
{ J5TT+FQ
nStartPos += fileAccessI.write(b,0,nRead); a`e'HQ
//if(nThreadID == 1) Wu~cy}\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K<rv|bJ
} ;A6%YY
,xw1B-dx
Tbp;xv_qo
Utility.log("Thread " + nThreadID + " is over!"); dAWB.#
bDownOver = true; <Hf3AB;#4
//nPos = fileAccessI.write (b,0,nRead); G{.[o6>
} Ct][B{
catch(Exception e){e.printStackTrace ();} DFkDlx
} bN\;m^xfu
} u\{MQB{T
Wsb>3J
25PZ&^G8%
//打印回应的头信息 J`]9n>G
public void logResponseHead(HttpURLConnection con) ^sKdN-{
{ (_%l[:o6
for(int i=1;;i++) s\zY^(v4
{ dl.gCiI
String header=con.getHeaderFieldKey(i); Cag^$nj
if(header!=null) w}]BJ<C
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0QP=$X
Utility.log(header+" : "+con.getHeaderField(header)); BOOb{kcg
else g`z;:ao
break; E~@&&dU8
} '7Mz]@
} Ze!/b|`xI
O _C<h
,\?s=D{
public void splitterStop() 6gabnW3
{ +Wl]1 c/
bStop = true; uO>x"D5tZ:
} 7Ll?#eun
Q45gC28x
QQ`tSYgex
} m@Dra2Cv'@
o~<jayqU
D<hX%VJ%M
/* <0VC`+p<)
**FileAccess.java xw}rFY$
*//文件访问(定位，写) blLl1Ak
package NetFox; H&8~"h6n
import java.io.*; s#'Vasu
e*}*3kw)T
3@nIoN'z
public class FileAccessI implements Serializable{ .]H/u "d
%+nM4)h
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M]|]b-#
RandomAccessFile oSavedFile; Y<IuwS
long nPos; Q;N)$Xx
:t9sAD
?V}ub>J/=
public FileAccessI() throws IOException -X_\3J
{ _&(L{cFx6
this("",0); T6b~uE
} F Uz1P
nuDu
<ne?;P1L
public FileAccessI(String sName,long nPos) throws IOException x+DETRLP
{ ;GE6S{~-
oSavedFile = new RandomAccessFile(sName,"rw"); dU*$V7
this.nPos = nPos; \!hd|j?&6
oSavedFile.seek(nPos); -Bq]E,Xf)
} x ;~;Ah.p
WJxcJE
u$CN$ynS
public synchronized int write(byte[] b,int nStart,int nLen) cNT !}8h^
{ |)v}\-\#
int n = -1; mU(v9Jpf7
try{ dWi<U4
oSavedFile.write(b,nStart,nLen); *o5[P\'6
n = nLen; QW'*^^
} Pl!E$
catch(IOException e) ju5o).!bg
{ +1I7K|M
e.printStackTrace (); "Bv V89
} :IU<AG6
Z t4q= Lr
Buso `G
return n; =E$bZe8
} A9g/At_
33KCO
(f^/KB=
} !vSq?!y6*P
/NjBC[P
auB 931|
/* :{^~&jgL
**SiteInfoBean.java c#CV5J\Kk3
*/ *3P+K:2lNG
package NetFox; &^K(9"
:Tv>)N
daP_Kz/2K
public class SiteInfoBean { *DvX||`&
g-jg;Ri
p^}`^>OL
private String sSiteURL; //Site's URL j'Jb+@W?
private String sFilePath; //Saved File's Path wd32q7lGo1
private String sFileName; //Saved File's Name j^;P=L0=
private int nSplitter; //Count of Splited Downloading File GqNOWK2O
"+4Jmf9
00'SceL=`
public SiteInfoBean() 8ki3>"!A
{//nSplitter的缺省值为5 mR|5$1[b
//default value of nSplitter is 5 4!OGNr$V@
this("","","",5); pEz^z9
} WtKKdL
?&zi{N
r7].48D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _;0RW
{ CS(XN>N
sSiteURL= sURL; 6FJ*eWPC
sFilePath = sPath; ,\X! :y~
sFileName = sName; 2z"<m2a
this.nSplitter = nSpiltter; 6]Q#4
94et ]u%7
YjnQ@IfIH
} - f ^!R
b{,v?7^4
w&T\8k=
public String getSSiteURL() Q"U%]2@=
{ *U6+b
return sSiteURL; ;du},>T$n
} /\<x8BJ
Z*f%R\u
bcvm]aPu
public void setSSiteURL(String value) ItvcN
{ yH]Q;X'
sSiteURL = value; '_V9FWDZ
} ]" e'z
~OsLbz:
N$#~&
public String getSFilePath() iPV-w_HQ
{ 2HSFMgy
return sFilePath; i$p2am8f
} - AgD
k!z<=WA
ja~Dp5
public void setSFilePath(String value) ! [1aP,
{ R&6@*Nn
sFilePath = value; $M4Z_zle)
} ybsw{[X>M
%7 yQ0'P
NOwd'iU
public String getSFileName() D!OY<?
{ 0HU0p!yt&
return sFileName; Z3YKG{g
} kaQNcMcq
uF|_6~g
i/n ee_
public void setSFileName(String value) *k_<|{>j(
{ j;b>~_ U%
sFileName = value; ~E((n
} _aOs8#(X
^'`(E_2u
i!8"T#
public int getNSplitter() ME0u|_dPjz
{ 7S 8X)
return nSplitter; yQ[;.<%v
} 9XtO#!+48
-`{W~yz
h!JyFc
public void setNSplitter(int nCount) b/qK/O8J
{ vdvnwzp!l
nSplitter = nCount; Kr'?h'F
} %Vltc4QU
} Yq51+\d
IO9|o!&>
\-]tvgA~&
/* n.a2%,|v
**Utility.java H"^9g3U
*/ f OR9N/
package NetFox; u&c%L0)E&
jQ'g'c!
T(Q ~b
public class Utility { ,g}$u'A+d
"= %"@"<)
jUNt4
public Utility() ](Wa:U}Xs
{ 2]9 2J
|n tWMm:(
>g>r_0.
} $\vNSTE
,{S $&g*
//线程睡眠 M&hNkJK*G
public static void sleep(int nSecond) 'R'hRMD9o
{ d7G@Z|R3p
try{ #k)z5vZ$h
Thread.sleep(nSecond); P2f^]z
} HBvyX`-
catch(Exception e) =v::N\&
{ .TdFI"Yn
e.printStackTrace (); ezL1,GT
} &dWGa+e
} ttJ'6lGXh
^78N25RU(
//日志 0AffD:
public static void log(String sMsg) <F&XT@
{ *A8*FX>\F
System.err.println(sMsg); &}Wi@;G]2
} 9M7P|Q
#yR&|*@
0\Jeyb2dl
public static void log(int sMsg) %JiF269
{ CP;<B1
System.err.println(sMsg); WHv6E!^\_
} @{fwM;me]P
} oz.z>+Q
bcy
v'?o#_La+
/* U7jDm>I
**TestMethod.java ]nebL{}5
*/ Rrry;Hr
package NetFox; :w5g!G?z
oVZzvK(zR
Kn1;=k
public class TestMethod { gy,)%{,G
X\H P{$fY_
Rzsu 7w
public TestMethod() j0~c2
{ ///xx/weblogic60b2_win.exe \6/Gy!0h-
try{ fgj$ u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /0gr?I1wr7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tCO?<QBE
SiteFileFetch fileFetch = new SiteFileFetch(bean); /%,aX[
fileFetch.start(); s:xJ }Ll
} 6Sn&;ap
catch(Exception e){e.printStackTrace ();} Z?=o(hkd
=8tK]lb
286reeN/e
} <+q`Dk
B[7,Hy,R
. 70=xH
public static void main(String[] args) Wp:vz']V
{ 11#b%dT
new TestMethod(); Ut'T!RD
} ,:J[|9
} #&r}J
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