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)); V|: qow:F
} Z&Pu8zG /m
for(int i=0;i<nEndPos.length-1;i++) lDN?|YG
{ q3+8]-9|5
nEndPos = nStartPos[i+1]; D/:3RZF
} %*K;np-q{
nEndPos[nEndPos.length-1] = nFileLength; YtYy zX5u7
} ?1w"IjUS
} ag;dc
FN\GE\H
kOI !~Qk
//启动子线程 "dtlME{Bx
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %/pc=i|+
for(int i=0;i<nStartPos.length;i++) &*gbK6JB
{ y-a|Lu*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E1(1E?}!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^P$7A]!
nStartPos,nEndPos,i); FYl3c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r?3Aqi"
fileSplitterFetch.start(); Yqj+hC6>,
} B9#;-QO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~kb{K;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PeNF+5s/K
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _ECB^s_
nEndPos = " + nFileLength); R=$Ls6z
// fileSplitterFetch[nPos.length-1].start(); Qxq-Mpx{
h<NRE0-
8Z8Y[p
//等待子线程结束 e=>%^F
//int count = 0; G~!C=l
//是否结束while循环 (B}+h
boolean breakWhile = false; 9g]M4*?C9P
qm%nIU \*
V^rW?Do
while(!bStop) S^j,f'2
{ jQ$BPEG&X
write_nPos(); zP nC=h|g
Utility.sleep(500); h(N=V|0
breakWhile = true; %5Rq1$D
GOVAb'
P%)b+H{$h
for(int i=0;i<nStartPos.length;i++) 0roCP=;
{ X| <yq
if(!fileSplitterFetch.bDownOver) fj+O'X
{ !^v\^Fc
breakWhile = false; WQKj]:qk0
break; OKPJuV`y6
} _tWE8r,
} T|bZ9_?+2
if(breakWhile) Xw^X&Pp
break; "&-C$J5 Id
uvv.WbZ
,Rz}=j
//count++; o;QZe&
//if(count>4) 3dm'xetM
// siteStop(); Ef,Cd[]b
} ~ 5"J(
[hHG.
jVYH;B%%z
System.err.println("文件下载结束！"); w+_Wc~f
} _9kIRmT{
catch(Exception e){e.printStackTrace ();} Tl3"PIb
} 6K 4+0xXv
YoAg
f:vD`Fz1
//获得文件长度 5\S&)ZA@
public long getFileSize() D]u=PqHk2
{ *P xf#X
int nFileLength = -1; #T"64%dX
try{ QJSr:dP4dG
URL url = new URL(siteInfoBean.getSSiteURL()); (\vXA4Oa,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); . r`[
httpConnection.setRequestProperty("User-Agent","NetFox"); c<tmj{$
:e2X/tl#
968^"T#
int responseCode=httpConnection.getResponseCode(); Eem g
if(responseCode>=400) $?f]ZyZr.
{ ";dU-\3M
processErrorCode(responseCode); e/94y6*>
return -2; //-2 represent access is error [z+x"9l0!
} >EIrw$V$
x'i0KF
#LWg"i
String sHeader; a))*F!}c
<25ccE9^c
3;Hd2 ;G
for(int i=1;;i++) g1V)$s7
{ s0!kwrBsp
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); voh^|(:(TH
//Utility.log(in.readLine()); $1e pf
sHeader=httpConnection.getHeaderFieldKey(i); 6~@5X}^<0
if(sHeader!=null) usH%dzKK
{ z2~87fv+
if(sHeader.equals("Content-Length")) ZNL5({lv
{ s=U\_koyH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xJc.pvVPw
break; [YE?OQ7#
} FL&dv
} TQ-KkH}y
else jL_5]pzJ
break; a}yR p
} VDn:SGj5
} )7AM3%z1?
catch(IOException e){e.printStackTrace ();} Efr3x{ j
catch(Exception e){e.printStackTrace ();} 4Py3I9
D|TR!
b1)\Zi
Utility.log(nFileLength); veO?k.u(
Z= ik{/
f4 O]`U
return nFileLength; 6[+j'pW?
} PbN3;c3
gh61H:tkR
<<<NXsH
//保存下载信息（文件指针位置） (&c,twa~
private void write_nPos() GNZ#q)qT
{ {(0Id!
try{ fTgbF{?xh
output = new DataOutputStream(new FileOutputStream(tmpFile)); }4KW@L[g
output.writeInt(nStartPos.length); zbg+6qs})
for(int i=0;i<nStartPos.length;i++) Pz1G<eh#{g
{ mu>] 9ZW
// output.writeLong(nPos); d?}hCo=/Xq
output.writeLong(fileSplitterFetch.nStartPos); ^U{P3%uZ
output.writeLong(fileSplitterFetch.nEndPos); ;@4sd%L8V
} 8!4[#y<
output.close(); 5L3{w+V
} #JFYws
catch(IOException e){e.printStackTrace ();} KBj@V6Q
catch(Exception e){e.printStackTrace ();} rkIMM,
} 1tyNRoET
Q@Dkl F
)Y8qWJU
//读取保存的下载信息（文件指针位置） _.-#E$6s#q
private void read_nPos() 8})|^%@n
{ tWX7dspx/
try{ wPQ&Di*X}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >uW^.e "F
int nCount = input.readInt(); -#OwJ*-U
nStartPos = new long[nCount]; b=G4MZQ
nEndPos = new long[nCount]; Yx 3|G
for(int i=0;i<nStartPos.length;i++) /N%zwj/*
{ g/B\ObY
nStartPos = input.readLong(); v^\JWPR/
nEndPos = input.readLong(); DZ2Fl>7
} f-&ATTx`J
input.close(); t)!V+Qcb
} 4znH$M>bU
catch(IOException e){e.printStackTrace ();} C$_G'XI
catch(Exception e){e.printStackTrace ();} 8=pv/o
} A$ J9U3+O
yWmrdvL
9BO|1{
private void processErrorCode(int nErrorCode) ,3k@L\$.x
{ 0}D-KvjyP
System.err.println("Error Code : " + nErrorCode); 4uPH
} H7}g!n?
>~^`5a`$uI
XJ O[[G`
//停止文件下载 nfa_8
public void siteStop() 8XlU%a6x
{ zF?31\GOX
bStop = true; gY%OhYtF2
for(int i=0;i<nStartPos.length;i++) qL,ka
fileSplitterFetch.splitterStop(); V07VwVD
@"0uM?_)-
#)FDl70S8
} 73VQ@Jn
} Ej{+U
//负责部分文件的抓取 !. p
**FileSplitterFetch.java hAlPl<BO#V
*/ m|lM.]2_
package NetFox; ]~'9
HmW=t}!
<c(&T<$
import java.io.*; lS#7xh
import java.net.*; B#QL M^
b]"2VN
}#&~w0P
public class FileSplitterFetch extends Thread { sbgJw
~};]k}
)=y.^@UT@
String sURL; //File URL $,.3&zsy
long nStartPos; //File Snippet Start Position $.``OxJk%
long nEndPos; //File Snippet End Position 40R"^*
int nThreadID; //Thread's ID =,O/,2)
boolean bDownOver = false; //Downing is over )dqR<)
boolean bStop = false; //Stop identical 7:z>+AM[r
FileAccessI fileAccessI = null; //File Access interface ' 4,y
hN[X 1*
*B%y`cj|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zf`5>h|
{ -Sx0qi'%
this.sURL = sURL; aXX,Zu^
this.nStartPos = nStart; 4{Q$!O>
this.nEndPos = nEnd; U7jhV,gO4
nThreadID = id; kp'b>&9r
fileAccessI = new FileAccessI(sName,nStartPos);//定位 J9NsHr:A[
} 'J2ewW5
JR])xPI`
,tau9>!
public void run() ix:2Z-
{ 33*^($bE&
while(nStartPos < nEndPos && !bStop) XMomFW_@
{ KuIkul9^%
d8rBu jT
GI}4,!^N
try{ SwyaYK
URL url = new URL(sURL); nT_*EC<.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F ~*zC`>Y
httpConnection.setRequestProperty("User-Agent","NetFox"); p@vpd
String sProperty = "bytes="+nStartPos+"-"; " 98/HzR
httpConnection.setRequestProperty("RANGE",sProperty); K1/ U (A
Utility.log(sProperty); uFz/PDOZ@
JvKO $^
*@CVYJ'<
InputStream input = httpConnection.getInputStream(); ?){0-A4
//logResponseHead(httpConnection); fDL3:%D
Yd[U
3(aRs?/O
byte[] b = new byte[1024]; u.$Ym
int nRead; D% oueW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bh{E&1sLh
{ [SK2x4
nStartPos += fileAccessI.write(b,0,nRead); ]gH wfqx
//if(nThreadID == 1) TViBCed40
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {F<)z%^
} )>ug{M%g
"w>rlsT<O
tX@0:RX%
Utility.log("Thread " + nThreadID + " is over!"); ]^Sd9ba
bDownOver = true; th5 X?so
//nPos = fileAccessI.write (b,0,nRead); C_6GOpl
} cR,'o'V/
catch(Exception e){e.printStackTrace ();} 65'`uuPx
} S4;wa6
} +G<}JJ'V
>?^~s(t
:uOZjEZi
//打印回应的头信息 z`c%?_EK
public void logResponseHead(HttpURLConnection con) Xq+!eOT
{ VEL:JsY
for(int i=1;;i++) FX{~"
{ " ]aQ Hh]f
String header=con.getHeaderFieldKey(i); AEB/8%l};v
if(header!=null) gmXy>{T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UAnB=L,.\
Utility.log(header+" : "+con.getHeaderField(header)); fn4=
else 5T~3$kuO
break; s;vWR^Ll
} 98X!uh'
} n/ui<&(
{CW1t5$*
KDux$V4
public void splitterStop() += X).X0K
{ v]B0!k&4.
bStop = true; jVLY!7Z4
} ='7er.~\
:&xz5c`"04
sjkWz2]S
} RpBiE8F4
AM>Yj
ck(CA(_
/* <f7?PAd
**FileAccess.java &?P=arU
*//文件访问(定位，写) \pjRv
package NetFox; lt@
import java.io.*; m-:8jA?
5}vRo;-
&p/S>qKu#
public class FileAccessI implements Serializable{ \hjk$Gq
s-QM6*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y}AmX
RandomAccessFile oSavedFile; ap Fs UsE
long nPos; *ge].E
W,QnU d'N
-9=M9}eDF
public FileAccessI() throws IOException L9E;Uii0
{ utYnaeQcn
this("",0); P5'iYahCq_
} XkMs
i_j9/k
1Z^`l6|2
public FileAccessI(String sName,long nPos) throws IOException 4M;sD;3
{ tQNk=}VR7r
oSavedFile = new RandomAccessFile(sName,"rw"); Tns?mQ
this.nPos = nPos; Z7tU0
oSavedFile.seek(nPos); .`oJcJ
} b&\3ps
jF%)Bhn(
r Iya\z1W
public synchronized int write(byte[] b,int nStart,int nLen) 71oFm1m{
{ -X"5G
int n = -1; tYI]LL
try{ V_)5Af3wY
oSavedFile.write(b,nStart,nLen); YQN]x}:E+4
n = nLen; l 'AK
} F/Rng'l
catch(IOException e) r;&]?9)W0
{ -mev%lV
e.printStackTrace (); c!'A)JD@
} LK'S)Jk
fhBO~o+K>
viW~'}^k7
return n; "D ts*
} Wrf^O2
tnQR<
uM6CG0
} (PCimT=5
OqfhCNAY
Bo\a
/* WUE)SVf
**SiteInfoBean.java ^kCk^D-Gz
*/ -XS+Uv
package NetFox; KKx&UKjV
9[epr+f
Jcwh|w9D8
public class SiteInfoBean { g|&.v2 '
J8sJ~FnUj
w0a+8gexi
private String sSiteURL; //Site's URL u+2xrzf
private String sFilePath; //Saved File's Path Yv#J`b@y
private String sFileName; //Saved File's Name |'V<>v.v
private int nSplitter; //Count of Splited Downloading File IqvqvHxLX
<GL}1W"Ay
ql#{=oGDnA
public SiteInfoBean() >,w\lf9
{//nSplitter的缺省值为5 rh:s 7
//default value of nSplitter is 5 tJ?qcT?
this("","","",5); `l[6rf_.
} 1S*8v7
w>NZRP_3
?/`C~e<J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W%Y.SP$Y
{ H{ n>KZ]\
sSiteURL= sURL; .c=$ bQ>^
sFilePath = sPath; "VT{1(]t
sFileName = sName; B|]t\(~$[
this.nSplitter = nSpiltter; ugIm:bg&
[M7iJcwt
IEno.i\
} >\6jb&,%O
Sah<sb=
}$&T O$LX
public String getSSiteURL() mr{k>Un\
{ xWenKY,
return sSiteURL; }AMYU>YE=
} %8Z|/LGg
<'>d0:>N
+BtLyQ
public void setSSiteURL(String value) yBYuDfeZ
{ )o " SB1
sSiteURL = value; K,lK\^y
} h@PMCmf_
dyQ<UT
^G'yaaLXR
public String getSFilePath() haEZp6Z
{ *#prSS
return sFilePath; \28b_,i+
} 2g ?Jb5)
=FtM;(\
F- !}dzO
public void setSFilePath(String value) *7xQp!w^
{ +YQ)}v
sFilePath = value; UZ4tq
} 4 BE:&A
]zhq.O >2{
V:,3OLL*
public String getSFileName() X*0eN3o.
{ C)&gL=O*$
return sFileName; _-|yCo
} tKs4}vW
;9!yh\\
,z0~mN
public void setSFileName(String value) ~L\(/[
{ Pq{YZMr
sFileName = value; 26('V `N
} ,{`o/F/
0btmao-
5H'b4Cyi`
public int getNSplitter() (04j4teE
{ Ru9pb~K
return nSplitter; 6?<`wGs(
} , IMT '*
EvH(Po h
W{$+mow7S
public void setNSplitter(int nCount) '$kS]U
{ tvj'{W
nSplitter = nCount; TeGLAt
} 6bRQL}[
} k<j)?_=`
r$3~bS$]
N) V7yo?
/* Ybn=Gy
**Utility.java VxPTh\O*[
*/ <750-d!
package NetFox; <@x+N%C
RBv=
$E4O^0%/p
public class Utility { X('Q;^`
`3>)BV<P
L!+[]tB
public Utility() ]mO+<{{4X
{ jKb=Zkd
8&2gM
_,K>u6N&
} H~_^w.P
RqX4ep5j
//线程睡眠 6M<mOhp@}n
public static void sleep(int nSecond) R^u^y{ohr
{ sxC{\iLY%
try{ S{"6PXzb
Thread.sleep(nSecond); @|\s$L
} [r/Seg"
catch(Exception e) `aX}.{.!
{ UQji7K }
e.printStackTrace (); zOu$H[
} i*cE
} j_ywG{Jk
G"UH4n[1ur
//日志 oVuj020
public static void log(String sMsg) xt<, (4u
{ p-(ADQS
System.err.println(sMsg); 9^Vx*KVrU
} d@>k\6%j
bbPd&7
q2j}64o_S
public static void log(int sMsg) Kz*AzB
{ *V@MAt
System.err.println(sMsg); g9lg
} H{tOCYyD
} g!kRa.`u1
-Bwu$$0
e,j?_p
/* K7&8;So
**TestMethod.java GE3U0w6WbK
*/ W%jX-
package NetFox; 4Igs\x{i
5Ret,~Vs9|
RWh}?vs_
public class TestMethod { W!Ct[t
:#&U95EC0
T=p}By3a
public TestMethod() ~E6+2t*
{ ///xx/weblogic60b2_win.exe @Qsg.9N3K
try{ &40JN}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); tL4]6u
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )i6U$,]
SiteFileFetch fileFetch = new SiteFileFetch(bean); $b 71
fileFetch.start(); 5_tK3Q8?
} u%IKM\
catch(Exception e){e.printStackTrace ();} ~PAbLSL*u
JU%yqXO
/qQ2@k
} ]#7Y@Yo
4[EO[x4C
v%8-Al^G
public static void main(String[] args) "}x70q'>S
{ `_{'?II
new TestMethod(); WO*WAP)n
} fvBC9^3
} zl8\jP
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