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)); @q]{s+#Xf
} 2u|}gZts
for(int i=0;i<nEndPos.length-1;i++) GwaU7[6
{ y!?l;xMS
nEndPos = nStartPos[i+1]; h_:|H8t;w
} 1V37% D
nEndPos[nEndPos.length-1] = nFileLength; &r Lg/UEV-
} $zuemjW3p
} ?Em*yc@WD
GP\Pk/E
-w:F8k ~
//启动子线程 7J@D})si
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =+j>?Yi
for(int i=0;i<nStartPos.length;i++) *PjW,
{ Q1?G7g]N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .OC{,f+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^#VyIF3q
nStartPos,nEndPos,i); gr")Jw7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }$ZcC_
fileSplitterFetch.start(); r&t)%R@q
} =?/RaK/ w
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *n=NBkq%/!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9V=bV=4:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j7)Xm,wI8
nEndPos = " + nFileLength); 2So7fZa^wg
// fileSplitterFetch[nPos.length-1].start(); U ExK|t
yEe4{j$
UldG0+1d
//等待子线程结束 d8? }69:h
//int count = 0; 1wpeYn7>W
//是否结束while循环 OyG$ ]C
boolean breakWhile = false; 007SA6xq
HV??B :
)MKzAAt~
while(!bStop) ;hOrLy&O
{ \=yx~c_$L
write_nPos(); \HB4ikl
Utility.sleep(500); 1cyX9X
breakWhile = true; /M-%]sayj
Jyx6{Oj
/ ` 7p'i
for(int i=0;i<nStartPos.length;i++) ;@@1$mzK
{ yH8 N8
if(!fileSplitterFetch.bDownOver) : qKxm(
{ +Zx+DW cq
breakWhile = false; z6K"}C%
break; qdB@P
} E:N~c'k
} _tg&_P+kV
if(breakWhile) Gv!* Qk4
break; ~$N%UQn?b#
/ W}Za&]
0.+"K}
//count++; Z%Nl<i
//if(count>4) mACj>0Z'
// siteStop(); uhFj|r$$
} szC~?]<YY
N.|Zh+!
@L8('8~d
System.err.println("文件下载结束！"); #L{QnV.3
} OgNt"Vg
catch(Exception e){e.printStackTrace ();} PF-7AIxs"
} 4425,AR
i51~/ R
.Z}ySd:X
//获得文件长度 \k1psqw^O
public long getFileSize() J(0.eD91v
{ h$p]#]uMb
int nFileLength = -1; Nw}y_Qf{
try{ !aD/I%X
URL url = new URL(siteInfoBean.getSSiteURL()); Zi=Nr3b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TE4{W4I
httpConnection.setRequestProperty("User-Agent","NetFox"); <a|$Bl
Ctxs]S tU%
Yw=Ve 0
int responseCode=httpConnection.getResponseCode(); #5kQn>R
if(responseCode>=400) |2\6X's
{ <@}~Fp@
processErrorCode(responseCode); *]fBd<(8
return -2; //-2 represent access is error d*=P8QwL|
} \+E{8&TH'
bIP{DxKS
\FSkI0
String sHeader; euS"C*
h5&l#>8&
NamBJ\2E1[
for(int i=1;;i++) &inu mc
{ q28i9$Yqj\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %_wX9ZT
//Utility.log(in.readLine()); lkK+Fm
sHeader=httpConnection.getHeaderFieldKey(i); @X_x?N
if(sHeader!=null) 2*-s3 >VK
{ T^8t<S@`
if(sHeader.equals("Content-Length")) iK6L\'k
{ nsqs*$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N.C<Mo
break; f0fN1
} 'H2TwSbIXI
} iIq='xwa9
else bR@ e6.<i
break; .Y!*6I
} zg&<HJO
} _|xO4{X
catch(IOException e){e.printStackTrace ();} "P=OpFV
catch(Exception e){e.printStackTrace ();} +?n81|7`
1vBR\!d?7
l;: L0(('
Utility.log(nFileLength); 'D8WNZ8Q
w1/pwzn
U7.3`qd"
return nFileLength; ~]DGf(
} V<AT"vU[
[y|"iSD
DPJ#Y -0
//保存下载信息（文件指针位置） M"2Tuwz
private void write_nPos() s)#FqB8
{ &IM;Yl
try{ *D1^Se
output = new DataOutputStream(new FileOutputStream(tmpFile)); mc;Z#"kf
output.writeInt(nStartPos.length); - *!R
for(int i=0;i<nStartPos.length;i++) Tm5]M$)
{ 9D:p~_"g
// output.writeLong(nPos); }<o.VY&;.
output.writeLong(fileSplitterFetch.nStartPos); jpZ, $
output.writeLong(fileSplitterFetch.nEndPos); ;sCf2TD,_
} \5 IB/*
output.close(); Y"~I(,nx!
} )y(pd
catch(IOException e){e.printStackTrace ();} zlZ$t{[,
catch(Exception e){e.printStackTrace ();} 40N8?kQ}?
} 5BCXI8Ox9x
EAU6z(X$
yf+M
//读取保存的下载信息（文件指针位置） [f}YXQ0N)
private void read_nPos() mOr>*uR
{ W~E%Eq3
try{ VS<E?JnbFV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i ~fkjn
int nCount = input.readInt(); Z9mY*}:U~
nStartPos = new long[nCount]; 6wx;grt'Z
nEndPos = new long[nCount]; k/YEUC5
for(int i=0;i<nStartPos.length;i++) T>s~bIzL*e
{ :l8n)O3
nStartPos = input.readLong(); D ::),,
nEndPos = input.readLong(); -! Hn,93
} L6Ykv/V
input.close(); HDZB)'I
} abkl)X>k
catch(IOException e){e.printStackTrace ();} W"+*%x
catch(Exception e){e.printStackTrace ();} _eM\ /(v[
} vFLQq,?Nh
blNJ
)#zc$D^U
private void processErrorCode(int nErrorCode) ~~k_A|&
{ rvuskXdo
System.err.println("Error Code : " + nErrorCode); MZ o\1tU-i
} z=B*s!G
Mfe/(tlI
Ehu^_HZ
//停止文件下载 `q7O\
public void siteStop() m8;; O
{ f4)fa yAVp
bStop = true; v{ Md4p
for(int i=0;i<nStartPos.length;i++) Tz3 L#0:j
fileSplitterFetch.splitterStop(); 9 o6ig>C
w~hO)1c],:
B}8xA}<
} fy" q
} 6/Y3#d
//负责部分文件的抓取 TJ8IYo| D
**FileSplitterFetch.java @9g$+_"ZT
*/ St9W{
package NetFox; p9Zi}!
=#dW^?p
;75K:_
import java.io.*; o<bZ.t
import java.net.*; /"?yB$s
E}Q'Wz|k
m(SGE,("w
public class FileSplitterFetch extends Thread { p/L|;c
?U.+SQ
mH2XwA|
String sURL; //File URL Tt#4dm-
long nStartPos; //File Snippet Start Position 0>Iy`>]
long nEndPos; //File Snippet End Position FIhq>L.q4
int nThreadID; //Thread's ID t?f2*N:
boolean bDownOver = false; //Downing is over fVx<f.xuW
boolean bStop = false; //Stop identical o^FlQy\
FileAccessI fileAccessI = null; //File Access interface :UM>`Y
~kPHf_B;z
]W39HL
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :,%~R2
{ $(B|$e^:(
this.sURL = sURL; xX$'u"dsA
this.nStartPos = nStart; >Q#h,x~vu
this.nEndPos = nEnd; T#kPn#|
nThreadID = id; 0w9)#e+JS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 tIfA]pE
} 3*x_S"h
AL@8v=
QG {KEj2V
public void run() \Fg%V>
{ 69ZGdN
while(nStartPos < nEndPos && !bStop) qww*
{ #v+2W
KGb:NQ=O6i
fNe9as
try{ ))m\d*
URL url = new URL(sURL); RQhS]y@e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =p~k5k4
httpConnection.setRequestProperty("User-Agent","NetFox"); tb36c<U-
String sProperty = "bytes="+nStartPos+"-"; \6AYx[|
httpConnection.setRequestProperty("RANGE",sProperty); hB/4.K]8
Utility.log(sProperty); a!rU+hiC
__N< B5E
VbX+`CwH
InputStream input = httpConnection.getInputStream(); 2GeJ\1k
//logResponseHead(httpConnection); art L
LkYcAY$w
|j:"n3~6
byte[] b = new byte[1024]; }2c)UQD8
int nRead; WjLy7&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :"QR;O@
{ yu3: Hv}
nStartPos += fileAccessI.write(b,0,nRead); *|WS,
//if(nThreadID == 1) \Gm$hTvB&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ok63 w7
} 'w//d $+G_
xVYy`_|
fNR2(8;}
Utility.log("Thread " + nThreadID + " is over!"); q,S[[{("
bDownOver = true; ZcJa:
//nPos = fileAccessI.write (b,0,nRead); G*;?&;*
} wJc~AP)I%z
catch(Exception e){e.printStackTrace ();} CVUA7eG+
} *Rm"3S
} ws}cMX]*
Xa o*h(Q@L
,', S
//打印回应的头信息 {3,_i66
public void logResponseHead(HttpURLConnection con) u}_,4J
{ lGoP(ki
for(int i=1;;i++) TOF_m$@#
{ 4mHR+SZy
String header=con.getHeaderFieldKey(i); s'$5]9$S
if(header!=null) ` mvPbZ0<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); K|^PHe
Utility.log(header+" : "+con.getHeaderField(header)); 80J87\)
else _A]8l52pt
break; }-`N^
} 1,Ams
} v=m!$~
s"OP[YEke/
9mA6nmp
public void splitterStop() HrOq>CSR
{ i28WgDG)5
bStop = true; `G/%U~
} aMv?D(Meb
2fqg,_
{L6@d1u
} b0VEMu81k
Q[PVkZ
ht>C6y
/* |:7 ^
**FileAccess.java {"v~1W)
*//文件访问(定位，写) +"mS<
package NetFox; l<3X:)
import java.io.*; )NF5,eD
%_P[ C}4
yP<ngi^s=
public class FileAccessI implements Serializable{ ujin+;1
/$[9-G?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [|qV*3|?
RandomAccessFile oSavedFile; ;-0 d2Z
long nPos; p]jkfsCjN
Ow"e3]}Mt
}>93X0%r
public FileAccessI() throws IOException 4 H<.
{ R!)3{cjU@
this("",0); T6ihEb$C
} ^Uq%-a
mV>l`&K=
we("#s1=
public FileAccessI(String sName,long nPos) throws IOException {{:QtkN
{ 9-/u _$
oSavedFile = new RandomAccessFile(sName,"rw"); s78MXS?py
this.nPos = nPos; /]1$Soo
oSavedFile.seek(nPos); ^5'pJ/BV
} EjA3hHJ
uqotVil,
nsA}A~(E
public synchronized int write(byte[] b,int nStart,int nLen) jT'09r3P
{ AONEUSxJ
int n = -1; a Fh9B\n
try{ !{1;wC(b
oSavedFile.write(b,nStart,nLen); olv0w;s
n = nLen; @k-C>h()C
} 2RbK##`vC
catch(IOException e) WrHY'
{ L*6R5i>
e.printStackTrace (); WEaG/)y
} 1fH2obI~X
8@ZZ[9kt
?W 6 :$
return n; Qx")D?u
} 79*f <Gr
9 _oAs"w
A+=K<e
} {1eW*9
P#!^9)3
|NdWx1
/* Q]{`m
**SiteInfoBean.java i7XM7+}
*/ H/2dVUU
package NetFox; | LXVf
]?7q%7-e.a
NNxzZ!q!
public class SiteInfoBean { <GWzdj?
n\i~H
pi|=3W
private String sSiteURL; //Site's URL ^`S.Mw.
private String sFilePath; //Saved File's Path S[;d\Z]~
private String sFileName; //Saved File's Name }`pxs
private int nSplitter; //Count of Splited Downloading File oh0*bh
-Hh.8(!XoO
p:NIRs
public SiteInfoBean() GYt|[GC
{//nSplitter的缺省值为5 )61X,z
//default value of nSplitter is 5 / q| o
this("","","",5); h'nXV{N0
} 8B`w!@hf
Fhrj$
,p>@:C/M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0z$::p$%u
{ i+Lqj
sSiteURL= sURL; `m`Y3I
sFilePath = sPath; %M*2j%6
sFileName = sName; G,}"}v:
this.nSplitter = nSpiltter; Y 8n*o3jM
9i46u20
Z8ds`KZM
} x~JOg57up
F.{$HJ
+>ld
public String getSSiteURL() {%oxzdPc
{ DJZ$M
return sSiteURL; sOO_J!bblP
} Aw]kQ\P&
ny"z<N&}/
MwC}
public void setSSiteURL(String value) K|Xr~\=
{ | Rj"}SC
sSiteURL = value; )A$xt)}P!{
} \ZtKaEXnx
gW-mXb
/PKu",Azj
public String getSFilePath() LC4W?']/
{ Bm5\*Xd1(
return sFilePath; feJl[3@tO
} !'#GdRstv
@\WeI"^F8
%i.Prckrb
public void setSFilePath(String value) fZp3g%u
{ |s,y/svp
sFilePath = value; K: |-s4=
} X4<Y5?&0
{TZV^gT4
DB+oCE<.#
public String getSFileName() bao"iv~z
{ FeNNzV=
return sFileName; w$Z%RF'p
} "vX\Q rL
8+ ]'2{
vSy[lB|)24
public void setSFileName(String value) :Y|[?;
{ r&+w)U~
sFileName = value; c,:nWf
} p^1~o/
S%jW}v';
X"sJiFS
public int getNSplitter() H*P[tyz$
{ {DapXx
return nSplitter; },@ex
} nkzH}F=<
Qff.QI,
Yd(<;JKF[
public void setNSplitter(int nCount) CQPq5/@Y4
{ XE]"RD<z
nSplitter = nCount; \&l@rMD3s
} B3<sSe8L0
} ~e&O?X
4peRbm
/Pxny3
/* xE{slDl
**Utility.java D/afa8>LQH
*/ eM@xs<BR
package NetFox; {:|b,ep T
tXuf!
.Q^V,[on1T
public class Utility { fRT4>So
mL-6+pJ@
oQA,57B
public Utility() Q/q>mN"#1
{ ExM VGe
.K]Uk/W
>?#zPweA
} l&*= .Zc7!
Dr76+9'i
//线程睡眠 JLt%G^W>
public static void sleep(int nSecond) ^X?uAX-RP|
{ "lrQC`?
try{ l"7#(a
Thread.sleep(nSecond); U~d%5?q
} 'Z]wh.]T
catch(Exception e) NTEN
{ rHi4Pw{L
e.printStackTrace (); `(ik2#B`}
} T2n3g|4
} S>)[n]f
%WC^aKfY
//日志 "%b Gwv
public static void log(String sMsg) 2m"cK^
{ pSI8"GwQ
System.err.println(sMsg); (AX$Svw
} ?bpVdm!
-:kIIK
J"Fp),
public static void log(int sMsg) 7#c4.9b?
{ N}1yDN
System.err.println(sMsg); . :>e"D
} #WJ*)$A@&
} 1{wbC)
8.>himL
]G D` f
/* \ @[Q3.VX
**TestMethod.java |fW_9={1kQ
*/ kv6nVlI)B
package NetFox; .wmqaLd%
&YcOmI/MM
N:okt)q:%
public class TestMethod { cRuN;
zWv0y8[d
yn"4qC#Z
public TestMethod() J .VZD
{ ///xx/weblogic60b2_win.exe O;5lF
try{ ?;H}5>^8P
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); x7Gf):,LK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ktS^^!,l%
SiteFileFetch fileFetch = new SiteFileFetch(bean); L|}s Z\2!
fileFetch.start(); [[w |
} nMZ)x-
catch(Exception e){e.printStackTrace ();} $:\`E56\
5KDCmw
oH!O{pQK}
} ,QpFVlPU
gWoUE7.3`
~ rQ,%dH
public static void main(String[] args) ?Pa(e)8\
{ Y9>92#aME
new TestMethod(); 'n ^,lXWB
} =*I|z+
} 8]exsnZ
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