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)); lUmaNZ
} R4?/7
for(int i=0;i<nEndPos.length-1;i++) r.[kD"l
{ ,b{4GU$3
nEndPos = nStartPos[i+1]; udMq>s;
} 3f0RMk$pH
nEndPos[nEndPos.length-1] = nFileLength; ~9=g"v
} V.qB3V$
} oT OMqR{"
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//启动子线程 8I%1 `V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ynhH5P|6,
for(int i=0;i<nStartPos.length;i++) ? T9-FGW
{ p)`JVq,H/B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @xo9'M<l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7y!{lr=n
nStartPos,nEndPos,i); Ad(j&P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); idHBz*3~ps
fileSplitterFetch.start(); YRFM1?*
} Dcq^C LPY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6B=J*8 Hs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); sHNt>5p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cOSUe_S0w[
nEndPos = " + nFileLength); hq|/XBd||
// fileSplitterFetch[nPos.length-1].start(); I?gbu@o
09r.0Ks
lq74Fz&(
//等待子线程结束 ^c*'O0y[D
//int count = 0; )9s[-W,e
//是否结束while循环 CAk.2C/
boolean breakWhile = false; +NQw^!0qy
n=`UhC
EG,RlmcPp
while(!bStop) +]G;_/[2
{ ?(Nls.c
write_nPos(); Xh5 z8
Utility.sleep(500); QM=X<?m/,=
breakWhile = true; 72aj4k]^
r!+)U#8
u?!p[y6
for(int i=0;i<nStartPos.length;i++) cYK3>p A
{ 5bk5EE`
if(!fileSplitterFetch.bDownOver) x@yF|8
{ Zi^&x6y^
breakWhile = false; uXXwMc<p
break; |,o!O39}>
} c}QjKJ-c
} rxO|k0x^C
if(breakWhile) BQsy)H`4E
break; 3vx?x39*Y
:2La,
I_Q'+d
//count++; Jf2
//if(count>4) 6 LC*X
// siteStop(); I%|W O*x
} US-P>yF
$%LjIeVA5
X=lOwPvP
System.err.println("文件下载结束！"); J*.qiUAgW
} mhL,:UE
catch(Exception e){e.printStackTrace ();} k@^)>J^
} LbnR=B!
;L|%H/SH
e(sQgtM6
//获得文件长度 oE}1D?3Sp
public long getFileSize() .-{B
{ ip~PF5
int nFileLength = -1; ^b'[81%
try{ A>Js`s
URL url = new URL(siteInfoBean.getSSiteURL()); C]82Mt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Jjv, )@yo
httpConnection.setRequestProperty("User-Agent","NetFox"); ZhW>H
Y<l{DmrsA
RV-7y^[]^
int responseCode=httpConnection.getResponseCode(); BDpeAF8z
if(responseCode>=400) %c):^;6p
{ ]*?qaIdqu
processErrorCode(responseCode); |:C=j/f
return -2; //-2 represent access is error $5l8V
} VUk2pEGO.
88G Q F
al1Uf]xh
String sHeader; 9 u{#S}c`
~!\n
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for(int i=1;;i++) r/SV.` k
{ Ji gc@@B.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .M!HVq47m
//Utility.log(in.readLine()); i!9yN:m0
sHeader=httpConnection.getHeaderFieldKey(i); >J+hu;I5
if(sHeader!=null) IZ"d s=w
{ vn7<>k>dx
if(sHeader.equals("Content-Length")) >O?5mfMK
{ }sZme3*J[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); y]yp8Bs+
break; x pT85D
} qhc3 oRe
} wpO-cJ!,
else 46Vx)xX
break; YQLp#
} |}t[-a
} ;vnG
catch(IOException e){e.printStackTrace ();} W&qE_r
catch(Exception e){e.printStackTrace ();} %&0_0BU
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zQ&`|kS
Utility.log(nFileLength); \:, dWLu
a!vF;J-Zqa
^h1EE=E"
return nFileLength; $5Jo%K%
} L> > %
:A.dlesv6
/Ii a>XY
//保存下载信息（文件指针位置） Mt"j< ]EW
private void write_nPos() C;QIp6"1
{ 0x*L"HD
try{ r&U5w^p
output = new DataOutputStream(new FileOutputStream(tmpFile)); F6`$5%$M;?
output.writeInt(nStartPos.length); ED[`Y.;
for(int i=0;i<nStartPos.length;i++) l@Uo4b^4x
{ gq\ulLyOeZ
// output.writeLong(nPos); $n.oY5=\
output.writeLong(fileSplitterFetch.nStartPos); eX;C.[&7;8
output.writeLong(fileSplitterFetch.nEndPos); CvS}U%
} Z(k7&^d
output.close(); ;rC)*=4#
} NBU[>P
catch(IOException e){e.printStackTrace ();} \$LrL
catch(Exception e){e.printStackTrace ();} 80DcM9^t8
} S2T~7-
!36jtKdM
4Hc+F(
//读取保存的下载信息（文件指针位置） q$7SJ.pF
private void read_nPos() }}y~\TB~}
{ ~`~mnlN
try{ z)*7LI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~\<aj(m(|
int nCount = input.readInt(); z]:{ruvH
nStartPos = new long[nCount]; ] ;"blB
nEndPos = new long[nCount]; 9M8n
for(int i=0;i<nStartPos.length;i++) _\uyS',
{ .sCi9d WR
nStartPos = input.readLong(); V/"P};n
nEndPos = input.readLong(); ancs
} X] cI ?
input.close(); I@ "%iYL
} tj7{[3~-[
catch(IOException e){e.printStackTrace ();} _8]hn[
catch(Exception e){e.printStackTrace ();} no).70K
} M@%$9N)gd
LVt{`
v 9\2/B
private void processErrorCode(int nErrorCode) h' #C$i
{ i^`]TOP
System.err.println("Error Code : " + nErrorCode); ^FJ.C|l(
} F-0|&0
/a@gE^TM
jG~zpZh
//停止文件下载 !0p_s;uu,W
public void siteStop() t|XQFb@}
{ %+0 7>/
bStop = true; (nL''#Ka
for(int i=0;i<nStartPos.length;i++) vG;)(.:
fileSplitterFetch.splitterStop(); *>"k/XUn$
a8$gXX-2
] /w:5o#
} w=Cqv~
} `q":i>FP2
//负责部分文件的抓取 9b88):[qO
**FileSplitterFetch.java BTi:Bcv k
*/ +OM`c7M:
package NetFox; EdgcdSb7
]m&cVy&
k?[|8H~2C
import java.io.*; bUJ5jkZ)
import java.net.*; 5^:N]Mp"
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_\mMgZu
public class FileSplitterFetch extends Thread { "'i" @CR
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String sURL; //File URL xweV8k/
long nStartPos; //File Snippet Start Position $d:>(_p=A
long nEndPos; //File Snippet End Position B}Lz#'5_
int nThreadID; //Thread's ID #*r u*
boolean bDownOver = false; //Downing is over 2pu8')'P
boolean bStop = false; //Stop identical g3*" ^C2=
FileAccessI fileAccessI = null; //File Access interface J^"
BC}+yS \
X"'c2gaa_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T8*<
{ O:K={#Xj
this.sURL = sURL; B6| g2Tt
this.nStartPos = nStart; X}UR\8g
this.nEndPos = nEnd; ^#:F8D
nThreadID = id; SY: gr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 YS7R8|
} ?<7o\Xk#{
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8Df(|>mK
public void run() TttD}`\.
{ i]sz*\P~
while(nStartPos < nEndPos && !bStop) =[X..<bW9:
{ %x Xib9J
io8c[#"uU
?uiQ'}
try{ e<Pbsj
URL url = new URL(sURL); $]H^?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Hjho!np
httpConnection.setRequestProperty("User-Agent","NetFox"); y}TiN!M
String sProperty = "bytes="+nStartPos+"-"; 1K<4Kz~
httpConnection.setRequestProperty("RANGE",sProperty); kZ^}
Utility.log(sProperty); g8I=s7cnb
}1N$4@
vO2I"Y*\
InputStream input = httpConnection.getInputStream(); -5v2E-
//logResponseHead(httpConnection); HW0EPJ
>=<qAkk
'%k<? *
byte[] b = new byte[1024]; c_oI?D9
int nRead; ~Z ,bd$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jSY&P/[xb
{ ~}B6E)
nStartPos += fileAccessI.write(b,0,nRead); ^4D7sS;~3
//if(nThreadID == 1) .'+*>y!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @I`X{oAA
} Qf?5"=:#
KZK9|121
)T4%}$(
Utility.log("Thread " + nThreadID + " is over!"); H[K(Tt4<&
bDownOver = true; iymOq9
//nPos = fileAccessI.write (b,0,nRead); JjH#,@'.
} {u/G!{N$
catch(Exception e){e.printStackTrace ();} Z @:5vo
} u!iBAr5
} ,}9G|$
*)PCPYB^
(6Ssk4
//打印回应的头信息 Cpyv@+;D
public void logResponseHead(HttpURLConnection con) <4caG2~q
{ b?h)~j5
for(int i=1;;i++) ) ?AlQA
{ ppwjr +
String header=con.getHeaderFieldKey(i); Y6_%HYI$
if(header!=null) < C{-ph
//responseHeaders.put(header,httpConnection.getHeaderField(header)); MT`gCvoF4P
Utility.log(header+" : "+con.getHeaderField(header)); a,B2;4"
else )+'De
break; c^N'g!on
} }]8n3&*
} 2!6+>nvO
0zSRk]i.f
dr25;L? B
public void splitterStop() 35 Y#eU2]
{ \t'v-x>2y5
bStop = true; )p,uZ`~v
} *6Ojv- G|5
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} |7ga9
aY/msplC
{i:5XL
/* &}TfJ=gj
**FileAccess.java k>W5ts2+
*//文件访问(定位，写) KJ7[DN'(
package NetFox; $jLJ&R=?]
import java.io.*; A7{l60(5
t}Z*2=DO
r*-e~
public class FileAccessI implements Serializable{ WYHr'xJ
/(`B;?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /EJwO3MW
RandomAccessFile oSavedFile; (IAc*V~
long nPos; 0SoU\/kUi
5<%]6cx}
=y5~7&9'
public FileAccessI() throws IOException V}leEf2'
{ KNR_upO8
this("",0); .zm'E<
} RVlAWw(
|FF"vRi8a7
3f 1@<7*
public FileAccessI(String sName,long nPos) throws IOException &VY(W{\eY
{ (-V=&F_
oSavedFile = new RandomAccessFile(sName,"rw"); oiG@_YtR
this.nPos = nPos; ~:65e 8K
oSavedFile.seek(nPos); ?J;*
} %s]l^RZ
c=S-g 9J
|!0R"lv'u
public synchronized int write(byte[] b,int nStart,int nLen) z8#c!h<@;
{ $6~ \xe=
int n = -1; 5H+S=
try{ R~jV
oSavedFile.write(b,nStart,nLen); U}c[oA
n = nLen; un+U_|>c
} lX)RG*FlTC
catch(IOException e) c)N&}hFYC
{ k'_p*H
e.printStackTrace (); i(eLE"G+
} M6ol/.G[
_g%Wx?K9
Q77iMb]
return n; NW}kvZ
} W#pA W
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!PCw-&
} =~Ac=j!q
?K<m.+4b*y
rUunf'w`e1
/* qXHr[C"
**SiteInfoBean.java $(2c0S{1
*/ s+"[S%
package NetFox; *^'$YVd#
_$OhV#LKG
!Ua74C
public class SiteInfoBean { R~-r8dWcw
"HWl7c3q
\wmNeGC2
private String sSiteURL; //Site's URL Ga4Ru
private String sFilePath; //Saved File's Path ~YxLDo'.t
private String sFileName; //Saved File's Name X#s:C=q1
private int nSplitter; //Count of Splited Downloading File !}sYPz]7!
OL{U^uOhY
m6qmZ2<
public SiteInfoBean() +C~,q{u
{//nSplitter的缺省值为5 gnS0$kCJ:
//default value of nSplitter is 5 &} b'cO
this("","","",5); !_+LmBd G
} %ZV a{Nc
kcH?l
Z`fm;7NiVG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *+p9u 1B5
{ ;SBM7fwRk
sSiteURL= sURL; @Q"%a`mKH
sFilePath = sPath; &hmyfH&S
sFileName = sName; PVAs# ~
this.nSplitter = nSpiltter; {7`eR2#Wq
MB<oWH[e)
[CH%(#>i~
} %m'd~#pze
1=DUFl.
>w:px$g4
public String getSSiteURL() ziuhS4k
{ H'uRgBjWJ
return sSiteURL; 2?LZW14$d
} -\;x>=#B
e![|-m%
IX eb6j8
public void setSSiteURL(String value) thk33ss:
{ CtbmX)vE
sSiteURL = value; <Bc J;X/
} f\oB/
GgH=w`;_
]Mv.Rul?~
public String getSFilePath() UzVnC:
{ P,Fs7
return sFilePath; *Yk3y-
} pCSR^ua>
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/nEh,<Y)
public void setSFilePath(String value) E Kks8
{ [wAI;=.
sFilePath = value; XW6>;:4k
} PTe8,cD>
&?(r#T
YPAMf&jEF
public String getSFileName() H"4^
{ `.+_}.m
return sFileName; d$<HMs:o@
} ]|[,N>
u\zRWX
wy&s~lpV,7
public void setSFileName(String value) :)+|q
{ 2<Pi2s'
sFileName = value; x72bufd
} MyZ@I7Fb,
|`9POl=
;4of7d
public int getNSplitter() E1:{5F5/
{ #_{3W-35*
return nSplitter; 0_Tr>hz
} f.0~HnNg1
mM"!=' z
`,ZsKxI
public void setNSplitter(int nCount) M xUj7ae
{ )sG`sET]`f
nSplitter = nCount; F+Og8^!
} +DS_'Tmr
} epi{Ayb
*M;!{)m?
-~eNC^t;W
/* !+&"y K@J
**Utility.java \{L!hAw
*/ WE\912j
package NetFox; D`3m%O(?
{:c*-+?
YuD2Q{
public class Utility { ]O s!=rt
),5^bl/
zDY!0QZLF\
public Utility() HF}%Ow
{ HjKj.fV
g@YJ#S(}
AQ 3n=Lr
} zghUwW|K
aoQK.7
//线程睡眠 m\|I.BUG
public static void sleep(int nSecond) MGeHccqh2
{ a6"Pe07t
try{ 2MmqGB}YcW
Thread.sleep(nSecond); @#Jc!p7)
} 'E+Ty(ED5
catch(Exception e) HMJx[ yD
{ l'T3RC,\
e.printStackTrace (); 0XFJ/
} O=8:K'
} .BJ;}
ac6Lv}w_
//日志 =ZjF5,@
public static void log(String sMsg) a)GLz
{ *A.E?9pL\
System.err.println(sMsg); HcwqVU
} %,$/wh)<V
^il'Q_-{
]&w>p#_C
public static void log(int sMsg) si,fs%D&
{ 3{ i'8
System.err.println(sMsg); +[Nc";Oy
} qT^R>p
} ta_!
5mdn77F_
6j@3C`Yd
/* "P`V|g
**TestMethod.java >t')ZSjRs
*/ :<f7;.
package NetFox; K?:rrd=7q
ST1PSuC~
_x_om#~n
public class TestMethod { EaGh`*"w(7
5hak'#2
-S\74hA
public TestMethod() Z?|\0GR+`5
{ ///xx/weblogic60b2_win.exe rr>*_67-:
try{ 1a4 [w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CsG1HR@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C4e3Itc9X
SiteFileFetch fileFetch = new SiteFileFetch(bean); )| @'}k+
fileFetch.start(); Ol3$!x9
} B;?)
catch(Exception e){e.printStackTrace ();} 1\t}pGSOeh
KW|X\1H
FI{9k(
} ,5Jq ZD
&PWz4hZ
?khwupdi
public static void main(String[] args) A$.woE@
{ [xq"[*Evv
new TestMethod(); 6=a($s!
} 26un=
} 0@z=0}0Z
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