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)); He_(JXTP
} q?]@' ^:;
for(int i=0;i<nEndPos.length-1;i++) ~1]2A[`s!
{ ~FCSq:_
nEndPos = nStartPos[i+1]; ?`*-QG}
} "drh+oo.
nEndPos[nEndPos.length-1] = nFileLength; a):Run
} @p` CAB
} SlJ/OcAf#
5Z1Do^
po$ynp756
//启动子线程 gwB>oi*OE
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; W;}u 2GH
for(int i=0;i<nStartPos.length;i++) 1*,~1!>
{ ?;#3U5$v
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hz|z&vyP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =O:ek#Bp
nStartPos,nEndPos,i); OVo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wj5s5dH
fileSplitterFetch.start(); ].T;x|
} $cpQ7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y#Sw>-zRq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); LW 3J$Am
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D}/.;]w<[&
nEndPos = " + nFileLength); LOG*K;v3
// fileSplitterFetch[nPos.length-1].start(); oYm{I ~"
?$&rC0t
MdboWE5i
//等待子线程结束 1YD.jU^;HD
//int count = 0; xjk|O;ak
//是否结束while循环 Dt'e<d Is
boolean breakWhile = false; 0]w[wc <
#cF8)GC
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while(!bStop) 4k?JxA)
{ 5%aKlx9^#
write_nPos(); Bv]wHPun
Utility.sleep(500); [)6E)E`_e
breakWhile = true; bme#G{[)Y
eKti+n.
FT<*
for(int i=0;i<nStartPos.length;i++) Gz5@1CF
{ 0Lz56e'j
if(!fileSplitterFetch.bDownOver) x]+KO)I
{ $"n)C
breakWhile = false; iKH T
break; 19{?w6G<k
} G:ngio]G0
} qa`(,iN
if(breakWhile) aYCzb7
break; ^X'7>{7Io
MW@b;=(
x(N}^Hu
//count++; {QkH%jj
//if(count>4) )g^Ewzy^X
// siteStop(); !e"m*S.(6{
} I2!HXMrp
0]0M>vx u
Guc^gq}
System.err.println("文件下载结束！"); ZGvNEjff
} 0=zS&xM
catch(Exception e){e.printStackTrace ();} *!s?hHv
} "A`'~]/hE
Z'm%3
B&j+fi
//获得文件长度 k8>^dZub
public long getFileSize() ' *C)S
{ D5vtZu!"
int nFileLength = -1; *n?:)(
try{ gy`qEY~B&
URL url = new URL(siteInfoBean.getSSiteURL()); mU>*NP(L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {X"]92+
httpConnection.setRequestProperty("User-Agent","NetFox"); 4c@F.I
:!FwF65
bdhgHjz
int responseCode=httpConnection.getResponseCode(); b#j5fEY
if(responseCode>=400) %d\+(:uu/
{ *heQ@ww
processErrorCode(responseCode); tV4aUve
return -2; //-2 represent access is error n}kz&,
} ^TK)_wx
d>psqmQ
Oip..f0
String sHeader; >G7U7R}R
HjR<4;2
"evV/Fg(
for(int i=1;;i++) `sC8ro@Fm
{ Vp4]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Bn:sN_N
//Utility.log(in.readLine()); r5wXuA,Um
sHeader=httpConnection.getHeaderFieldKey(i); -e\56%\~_
if(sHeader!=null) K6hNN$F!
{ sxa (
if(sHeader.equals("Content-Length")) K#m o+n5-;
{ 6E4L4Vb
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &>t1A5
break; /omVMu
} DO{4n1-U
} "ET"dMxU
else [wYQP6Cyy
break; .1}(Bywm5
} j pV
} cXH?'q'vZ
catch(IOException e){e.printStackTrace ();} H>9$L~
catch(Exception e){e.printStackTrace ();} .?NAq[H%
9Ua@-
}"tYb6*
Utility.log(nFileLength); !1R
~=*_I4,+r
')<$AMy1
return nFileLength; Y [S^&pF
} inrL'z
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yRDLg c
//保存下载信息（文件指针位置） ;oE4,
private void write_nPos() ;_*F [ }w
{ 7]bqs"t
try{ $<PVzW,$o
output = new DataOutputStream(new FileOutputStream(tmpFile)); T94$}- 5/)
output.writeInt(nStartPos.length); KQ3 On(d
for(int i=0;i<nStartPos.length;i++) krU2S-
{ } q(0uzaG
// output.writeLong(nPos); u{ /gjv
output.writeLong(fileSplitterFetch.nStartPos); Jsl,r+'H
output.writeLong(fileSplitterFetch.nEndPos); +a;j>hh
} 9 |Y?#oZ1
output.close(); ]B||S7idq
} cPSu!u}D
catch(IOException e){e.printStackTrace ();} 5N/;'ySAE_
catch(Exception e){e.printStackTrace ();} kEh# 0
} +/tD$
9mZ1 a6,x
B%/Pn 2
//读取保存的下载信息（文件指针位置） 0:EiCKb)ol
private void read_nPos() 0M p>X
{ `x{gF8GV
try{ g&V.o5jIhc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wd*Jq
int nCount = input.readInt(); rOGJ%|%(
nStartPos = new long[nCount]; `OWB@_u5
nEndPos = new long[nCount]; Ql 1# l:Q
for(int i=0;i<nStartPos.length;i++) o hCPNm
{ T}*'9TB
nStartPos = input.readLong(); xAflcY>Ozs
nEndPos = input.readLong(); ';%g^!lM a
} {JJ`|*H$_
input.close(); $oEDyC
} j06DP _9M
catch(IOException e){e.printStackTrace ();} /e\dsC{uJ
catch(Exception e){e.printStackTrace ();} )d~Mag+
} ` {p5SYj
K^ lVng
<Jx{Uv
private void processErrorCode(int nErrorCode) |j<'[gB\p
{ B$G8,3,:
System.err.println("Error Code : " + nErrorCode); ~A)$="
} RfD$@q9
{mDaK&]Oh
7blZAA?-
//停止文件下载 tj0vB]c
public void siteStop() G+}LLm.wX
{ S^u!/ =&
bStop = true; @N$r'@
for(int i=0;i<nStartPos.length;i++) BI s!
fileSplitterFetch.splitterStop(); g6farLBF
@fwU%S[v
c?d#Bj ?
} `#V"@Go
} Am0$UeSZ
//负责部分文件的抓取 DCm;dh
**FileSplitterFetch.java )UeG2dXx7
*/ _:z~P<%s
package NetFox; .&ZVy{uP
) E\pQ5&
=YBJ7.Y
import java.io.*; <i5^izg
import java.net.*; BC+HP9<]
3O.-'U1K
:X#(T-!t
public class FileSplitterFetch extends Thread { z(xvt>
]1K &U5p
|lv4X}H
String sURL; //File URL `'>>[*06:a
long nStartPos; //File Snippet Start Position OKP?^%kD
long nEndPos; //File Snippet End Position s-*XAnot
int nThreadID; //Thread's ID OjHBzrK
boolean bDownOver = false; //Downing is over Pzqgg43Xf
boolean bStop = false; //Stop identical H`P )
FileAccessI fileAccessI = null; //File Access interface 1li`+~L F
;?rW`e2
b7n~z1$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9#p^Z)[)-
{ e#seqx
this.sURL = sURL; kB 2bT}
this.nStartPos = nStart; 0\mzGfd
this.nEndPos = nEnd; kahv1s-
nThreadID = id; %[0"[<1a
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C"sa.#}
} kK(633s
|!|`Je3 K
FR <wp
public void run() %nIjRmqM~
{ myo/}58Nv
while(nStartPos < nEndPos && !bStop) #G,e]{gs
{ `>*P(yIN
wK3}K
A-~)7-
try{ 4 qnQF]4
URL url = new URL(sURL); OJ 2M_q)e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,kP{3.#Q
httpConnection.setRequestProperty("User-Agent","NetFox"); f9$98SI
String sProperty = "bytes="+nStartPos+"-"; 7+c@pEU]
httpConnection.setRequestProperty("RANGE",sProperty); vH=I#Ajar
Utility.log(sProperty); suVS!} C
%6n;B|!
3lJK[V{'#'
InputStream input = httpConnection.getInputStream(); B4b UcYk
//logResponseHead(httpConnection); Ii9vA ^53
*-n$n
<D=%55
byte[] b = new byte[1024]; P)H%dJ^l
int nRead; QK72F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }X$>84s>[P
{ hk=+t&Y<H
nStartPos += fileAccessI.write(b,0,nRead); Pk,^q8;
//if(nThreadID == 1) 7}*5Mir p
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $OJ*Kul
} e#AB0-f
wjl?@K
q q`UvU
Utility.log("Thread " + nThreadID + " is over!"); $lv g.u
bDownOver = true; 4M:oa#gh@
//nPos = fileAccessI.write (b,0,nRead); <sTaXaq?
} Cr&ua|%F
catch(Exception e){e.printStackTrace ();} T7,tJk,(
} "}!vYr
} Vf:t!'WD?2
OS!47Z /q
4, :D4WYWD
//打印回应的头信息 @<YZa$`
public void logResponseHead(HttpURLConnection con) 0+L5k!1D
{ ^^[,aBu
for(int i=1;;i++) $yt|nO
{ CN >q`[!
String header=con.getHeaderFieldKey(i); {S}/LSNB
if(header!=null) .-r 1.'.A
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mF_/Rhu
Utility.log(header+" : "+con.getHeaderField(header)); A^~\
else $Fn# b|e
break; \&cVcAg
} l+#`
} LWW0lG!_F
>1r>cZn
%=|I;kI?
public void splitterStop() o(a*Fk$
{ )S`A+M K]
bStop = true; \UiuJ+
} :s4CWEd
aH:eu<s
9|go`^*.
} I[R?j?$}>
o~~_>V)W
~r{Nc j
/* ljk-xC p/
**FileAccess.java *BF1Sso
*//文件访问(定位，写) { u;ntDr
package NetFox; _x:K%1_[
import java.io.*; R%ddB D\?
=\q3;5[
#3qkG)
public class FileAccessI implements Serializable{ 2Gj&7A3b
lKm?Xu'yH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 co;2s-X
RandomAccessFile oSavedFile; ;eWVc;H
long nPos; #)\KV7f!;
'al-C;Z
9eV@v
public FileAccessI() throws IOException wwF20
{ =]D##R
this("",0); aMzAA
} f[X>?{q
10a=[\ Q
b)df V=
public FileAccessI(String sName,long nPos) throws IOException 1e&`m~5K+
{ 2\7]EW
oSavedFile = new RandomAccessFile(sName,"rw"); kQj8;LU
this.nPos = nPos; 8]0R[kjD
oSavedFile.seek(nPos); 8*|@A6ig
} j6Vuj/+}
;z&p(e
Y#Hf\8r,d
public synchronized int write(byte[] b,int nStart,int nLen) ^+}<Q#y-
{ VJwzYl
int n = -1; pa.W-qyu
try{ R=E )j^<F
oSavedFile.write(b,nStart,nLen); v!W,h2:J
n = nLen; k1]?d7g$w
} 44n^21k
catch(IOException e) GSMP)8W
{ }+u<^7$g|
e.printStackTrace (); JNZKzyJ9K
} ;KnnAZJ
6-<r@{m$
=!p6}5Z
return n; 8(ZQD+U(9F
} h883pe=
af> i
`f b}cJUa
} ql],Wplg
~DCw [y
d`v]+HK
/* PI }A')Nq.
**SiteInfoBean.java Fn6>n04v
*/ >bmL;)mc&
package NetFox; bZ0r/f,n$
]2v31'
}bHdU]$}
public class SiteInfoBean { f\Pd#$3
2p@S-Lp
c1Dhx,]ad
private String sSiteURL; //Site's URL Z>o20uA
private String sFilePath; //Saved File's Path G`w7dn;&
private String sFileName; //Saved File's Name ]x~H"<V
private int nSplitter; //Count of Splited Downloading File zaX30e:R
=7Nm=5@
\<V{6#Q=
public SiteInfoBean() IspY%UMl
{//nSplitter的缺省值为5 &x\u.wIa
//default value of nSplitter is 5 *-gS u
this("","","",5); U+nwLxe'
} Ib]{rmaP
tz2`X V{
'%)7%O,2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Rh~<#"G]
{ 1 aIJ0#nE
sSiteURL= sURL; HHT K{X+
sFilePath = sPath; )PR{ia64;<
sFileName = sName; aQkgkV;~
this.nSplitter = nSpiltter; skr^m%W
:fo%)_Jc!
;Q-(tGd
} % &{>oEQ
(5VP*67
<+C]^*j
public String getSSiteURL() *h$Dh5%P
{ fMd]P:B
return sSiteURL; L;>tuJY1
} G^oBu^bq~
^-mz!{
~E#>2Mh
public void setSSiteURL(String value) R)ejIKtY
{ ll73}v
sSiteURL = value; v?5Xx{ym
} omY%sQ{)
TRG"fVR
&QLCij5:
public String getSFilePath() Cd]d[{NJ;
{ <#LHL
return sFilePath; EzwYqw
} 61b,+'-
:,6dW?mun6
Peh(*D{
public void setSFilePath(String value) R7( + ^%
{ l8n#sGA%
sFilePath = value; 7[^:[OEE
} <HI5xB_
G23Mr9m5O
v~uQ_ae$>
public String getSFileName() H+\rCefba
{ 1KAA(W;nq
return sFileName; !uy?]l
} H>a3\M
K-(,,wS
)%f]`<o
public void setSFileName(String value) {b8!YbG
{ |s[m;Qm[ku
sFileName = value; i%D/@$\D6
} ,m9Nd "6\
78Nli/U
m},nKsO
public int getNSplitter() ,bKA]#(2
{ <j-Bj$3
return nSplitter; ')}$v+9h
} {>pB
{.DI[@.g
YLJH?=2@
public void setNSplitter(int nCount) 7f~DD8R
{ R1\cAP^0
nSplitter = nCount; >5i1M^g(
} o#4Wn'E
} E_/v$
2p8JqZMQb
MuO7_*q'n
/* 9Or3X/:o
**Utility.java :~{XL>:S
*/ x.<^L] "
package NetFox; LdDkd(k
'h([Y8p{
Wi'BX#xCB
public class Utility { gjk=`lU
>rB7ms/@E
WB"$NYB
public Utility() '[{M"S
{ *B#<5<T
x{&0:|bCs6
1Hy
} j}X4#{jgC
s"=e(ob
//线程睡眠 gPd:>$
public static void sleep(int nSecond) 6JSa:Q>,
{ 69`9!heu
try{ iEsI
Thread.sleep(nSecond); k$7-F3
} s[SzE6eQ`l
catch(Exception e) *;1G+Q#
{ VQ$=F8ivG
e.printStackTrace (); 7'xT)~*$4
} A!ba_14
} jgs kK
"mSDL:$
//日志 ZL+{?1&-
public static void log(String sMsg) );@@>~
{ 4&R\6!*s
System.err.println(sMsg); ACU0
} B@63=a*kG
)><cL:IJ}S
_r+9S.z
public static void log(int sMsg) KQNSYI7a
{ !-|&
System.err.println(sMsg); )Mi#{5z
} _(0!bUs>
} mRW(]OFIai
{t;Q#Ou.
3BKW
/* !,V8?3.aJn
**TestMethod.java }V ;PaX
*/ QtW5;A-h
package NetFox; TXH: +mc
tPDV"Md#m<
M#=woj&[
public class TestMethod { Bb}JyT
ygd'Nh!@
%&V<kH"7Q{
public TestMethod() A&Ut:OiA
{ ///xx/weblogic60b2_win.exe UY+~,a
try{ R0gjx"U
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jQ4Pv`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6(ju!pE`
SiteFileFetch fileFetch = new SiteFileFetch(bean); hkRv0q.'
fileFetch.start(); ]W5s!T_
} s><RL]+{G+
catch(Exception e){e.printStackTrace ();} >M[rOu (d
)qzJu*cQ
8Nd +
} ?$Uk[
>Cb% `pe
@Ys(j$U't
public static void main(String[] args) 8:huWjh]M
{ R 7xV{o
new TestMethod(); s%H5Qa+Uh
} $gJMF(
} x1|5q/I
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