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)); S#l)|c_~
} xPMX\aI|l
for(int i=0;i<nEndPos.length-1;i++) 3yu,qb'"&
{ #Ti5G"C
nEndPos = nStartPos[i+1]; /Y8{?
} v<E_n;@9k
nEndPos[nEndPos.length-1] = nFileLength; vg\fBHzn
} 5](,N^u{):
} LEA^o"NW.
3$PGLM
<^"0A
//启动子线程 N[wyi&m4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w%eEj.MI|i
for(int i=0;i<nStartPos.length;i++) VV"1IR
{ 28O3N;a
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M4K>/-9X+V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), z6'l" D'h
nStartPos,nEndPos,i); 79}Qj7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >:P-3#e*
fileSplitterFetch.start(); 2fG[q3`
} "2GssBa
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {%QWv%|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vf?m-wh
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7F8>w 7Y]
nEndPos = " + nFileLength); GtkZ%<KF9
// fileSplitterFetch[nPos.length-1].start(); V?4G~~F
T9]:, z
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//等待子线程结束 *.zC9Y,
//int count = 0; &u0on)E
//是否结束while循环 E\XD~
boolean breakWhile = false; H)NT2@%{P
v}&J*}_XZ
ci`N,&:R
while(!bStop) S/Gy:GIf
{ c'Zs2s7$
write_nPos(); 8~vE
Utility.sleep(500); $GX9-^og=T
breakWhile = true; D]hwG0Chd
~%u;lr
%$zX a%A
for(int i=0;i<nStartPos.length;i++) zzZK S
{ FoGSCg%
if(!fileSplitterFetch.bDownOver) 6"|+\
{ z?Qt%1q
breakWhile = false; ui1h M
break; pR7D3Q:^7
} Hb@PQcj
} _A=Pr_kN
if(breakWhile) 8% `Jf`
break; <jtu/U]78|
6"_ytqw7
;p/$9b.0:
//count++; LABLT;c
//if(count>4) dS~#Lzm
// siteStop(); zM++Z*
} }XIUz|
Oo8"s+G
1|3{.Ed
System.err.println("文件下载结束！"); m7NrS?7
} SMbhJ}\O
catch(Exception e){e.printStackTrace ();} ql%]t~HR0
} 4 X6_p(
uz[5h0c
QOKE9R#Y
//获得文件长度 D7OPFN7`
public long getFileSize() yZqX[U
{ Ah1fcXED
int nFileLength = -1; S_Ug=8r4
try{ +G[N lb
URL url = new URL(siteInfoBean.getSSiteURL()); (}&O)3)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [Z{0|NR
httpConnection.setRequestProperty("User-Agent","NetFox"); 0Nq6>^ %
KImazS^
f)%8*B
int responseCode=httpConnection.getResponseCode(); wEMg~Hh
if(responseCode>=400) -KFozwr5/
{ @#KZ2^
processErrorCode(responseCode); ^{w]r5d
return -2; //-2 represent access is error E>3(ff&
} \KT}T
q8P$Md-=b1
&kNJs{
String sHeader; j3)fmlA
J:JkX>n%k=
N!W2O>VS
for(int i=1;;i++) $ru()/pI)z
{ K!BS?n;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3F|#nq
//Utility.log(in.readLine()); cuW&X9\m,
sHeader=httpConnection.getHeaderFieldKey(i); ~(/OB w
if(sHeader!=null) i\z,)xp
{ (_$'e%G0
if(sHeader.equals("Content-Length")) 0N(o)WRv
{ 13KfI
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =TG[isC/F9
break; <u%&@G$F>
} f hS4Gb_
} T\Ld)'fNv
else {e'V^l.v
break; uDXRw*rTv
} \>@QJ
} eod-N}o
catch(IOException e){e.printStackTrace ();} }:2GD0Ru
catch(Exception e){e.printStackTrace ();} `$N()P
FyV)Nmc%t
(viGL|Ogn
Utility.log(nFileLength); />q?H)6
F.[E;gOTo
(h3f$
return nFileLength; Oj~4uT&"
} ym~
_cw~N p
EiP#xjn?c
//保存下载信息（文件指针位置） [@LA<Z_
private void write_nPos() {i09e1
{ 8M&q
try{ v62M8r,Y
output = new DataOutputStream(new FileOutputStream(tmpFile)); { *&Wc Os
output.writeInt(nStartPos.length); O h{>xg
for(int i=0;i<nStartPos.length;i++) 1U(P0$C
{ #Z)8,N
// output.writeLong(nPos); ^vA"3Ixb!
output.writeLong(fileSplitterFetch.nStartPos); N&]GPl0
output.writeLong(fileSplitterFetch.nEndPos); B !}/4"
} u{+z?N
output.close(); ,/uVq G
} BhcTPQsW
catch(IOException e){e.printStackTrace ();} R@[gkj
catch(Exception e){e.printStackTrace ();} #o/
} %{*A@jQsg
<bbC&O\
9J $"Qt5;6
//读取保存的下载信息（文件指针位置） Uxl7O4J@H
private void read_nPos() }S,KUH.
{ 3 J!J#
try{ a2!;$B%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bnYd19>
int nCount = input.readInt(); |h6u%t2AY
nStartPos = new long[nCount]; *@(j'0hj
nEndPos = new long[nCount]; XQhbH^
for(int i=0;i<nStartPos.length;i++) X<*-d6?gD`
{ W~i599!v
nStartPos = input.readLong(); |[B JZ
nEndPos = input.readLong(); T5gL
} Rxfhk,I
input.close(); j+6`nN7L
} 8[\~}Q6
catch(IOException e){e.printStackTrace ();} kx.8VUoM V
catch(Exception e){e.printStackTrace ();} ]r\d 5
} fUV;3du
W0qn$H
`vc?*"
private void processErrorCode(int nErrorCode) >= VCKN2'j
{ p/WE[8U
System.err.println("Error Code : " + nErrorCode); UJ^MS4;I3
} 3Q\k!$zq
_p^&]eQ+k#
2Cgq&\wS
//停止文件下载 ul!e!^qwx
public void siteStop() og)f?4
{ oa q!<lI
bStop = true; $s,Az_bs
for(int i=0;i<nStartPos.length;i++) l1uv]t <
fileSplitterFetch.splitterStop(); c)B <d#
mVVL[z2+
8d|#W
} K^f&+`v6_
} trm-&e7q?;
//负责部分文件的抓取 y??^[ sB
**FileSplitterFetch.java gWLhO|y
*/ ToE^%J4
package NetFox; DR c-L$bD
ywkyxt
sB+ B,DF
import java.io.*; \_|g}&}6Y
import java.net.*; D9/PVd&#
Ds@nuQ
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public class FileSplitterFetch extends Thread { L/*K4xQ
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j~C-T%kYa
String sURL; //File URL XZH\HK)K-]
long nStartPos; //File Snippet Start Position &{zRuF
long nEndPos; //File Snippet End Position rfHAz
int nThreadID; //Thread's ID I|/\L|vo
boolean bDownOver = false; //Downing is over @0&KM|+
boolean bStop = false; //Stop identical 56 [+;*
FileAccessI fileAccessI = null; //File Access interface /j$`Cq3I
y@2$sK3K
q:vc;y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >))K%\p
{ F*J@OY8i
this.sURL = sURL; mr<camL5
this.nStartPos = nStart; {No Y`j5S
this.nEndPos = nEnd; 'Fr"96C$
nThreadID = id; X|Rw;FY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pWOK~=t
} n1PV/ Z
AZf$XHP2
Y wu > k
public void run() aM!%EaT
{ .)[0yW&
while(nStartPos < nEndPos && !bStop) 0.z\YTZ9
{ D V=xqC6}
N"-U)d-.
s~g0VNu Y
try{ {jOV8SVL
URL url = new URL(sURL); =BroH\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ..;ep2jSs
httpConnection.setRequestProperty("User-Agent","NetFox"); 9six]T
String sProperty = "bytes="+nStartPos+"-"; ~jDf,a2
httpConnection.setRequestProperty("RANGE",sProperty); _0h)O
Utility.log(sProperty); aU?HIIA
Yc2dq e>
?~=5x
InputStream input = httpConnection.getInputStream(); <gu>06
//logResponseHead(httpConnection); ?4H>1Wkb
"a=dx| Z
Y^-D'2P]P
byte[] b = new byte[1024]; |<!xD iB
int nRead; E@CK.-N|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,lb >
{ PsO>&Te2
nStartPos += fileAccessI.write(b,0,nRead); cxpG6c
//if(nThreadID == 1) (,;4f7\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >^J
} bTc^huP
>B$J
n0%5mTUN
Utility.log("Thread " + nThreadID + " is over!"); >?|c>HGX
bDownOver = true; z6uHe{|
//nPos = fileAccessI.write (b,0,nRead); tNC;CP#R+
} 4;V;8a\A
catch(Exception e){e.printStackTrace ();} ;X%8I$Ba,
} 4b 1a?
} wOn*QO[
1HBWOV7z.?
DSL3+%KF#
//打印回应的头信息 EFzPt?l
public void logResponseHead(HttpURLConnection con) tKYg
{ S0H|:J
for(int i=1;;i++) 9O|k|FD
{ e`bP=7`0
String header=con.getHeaderFieldKey(i); ()(^B}VK
if(header!=null) U$Od)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .tA=5QY,
Utility.log(header+" : "+con.getHeaderField(header)); C"R}_C|r)*
else q]#j,}cN9
break; :uB(PeAv*
} ui<Mnm_T;d
} #+(@i|!ifo
=h,J!0Y
bA\(oD+:
public void splitterStop() $%.,=~W7
{ VYnB&3%DF
bStop = true; rAh|r}R
} +c' n,O~3
349BQ5ND
P1dFoQz
} IubzHf
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0.0r?T
/* (je`sV
**FileAccess.java ZDx1v_xr
*//文件访问(定位，写) cS(=wC
package NetFox; FB2{qG3
import java.io.*; *r|Zbxf(
?G 'sb}.
?^WX]SAl
public class FileAccessI implements Serializable{ iHeu<3O
tY%T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p<c1$O*
RandomAccessFile oSavedFile; ;jh.\a_\
long nPos; qAi:F=> X
iz3Hoj
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public FileAccessI() throws IOException K6stkDhb
{ ? kCo/sW
this("",0); #6mr'e1
} 6\USeZh
B/dJj#
y(X^wC
public FileAccessI(String sName,long nPos) throws IOException )!=fy']
{ zQoJ8i>
oSavedFile = new RandomAccessFile(sName,"rw"); ;i!$rL
this.nPos = nPos; R0e!b+MZ.
oSavedFile.seek(nPos); FTu<$`!1L
} Sobp;OZ5
3j2d&*0
>N"=10
public synchronized int write(byte[] b,int nStart,int nLen) 7>f)pfLM
{ \jr-^n]
int n = -1; jQ['f\R
try{ {7.uwIW.1
oSavedFile.write(b,nStart,nLen); 9Us'Q{CD
n = nLen; !'Ww%ZL\
} 1rV9dM#F
catch(IOException e) |Elz{i-
{ et<@3wyd]
e.printStackTrace (); u.2^t:A
} '![VA8
/w2NO9Q
(zw.?ADPCT
return n; U04)XfO;]
} XsX];I{E,
[6)vD@
n<Ki.;-ZE
} x$KQ*P~q
3 <Zo{;
A_+*b [P
/* TIxlLOs
**SiteInfoBean.java USH>`3
*/ :Yn{:%p
package NetFox; ~R7{gCqdr
ceAefKdb
A:*$rHbzl
public class SiteInfoBean { [Vj|fy4
r@ba1*y0
&Qt1~#1
private String sSiteURL; //Site's URL (, $Lp0mB7
private String sFilePath; //Saved File's Path |T{ZDJ+
private String sFileName; //Saved File's Name ^9XAWj"
private int nSplitter; //Count of Splited Downloading File Ox6^=D"
ZK8DziO
@}{Fw;,(7n
public SiteInfoBean() c[EG cY={
{//nSplitter的缺省值为5 *2Q x69`
//default value of nSplitter is 5 yn04[PN2
this("","","",5); xI8v'[3
} 2G$-:4B
Q`UgtL
]o`FF="at
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) vr$z6m ^
{ #J%Fi).^)
sSiteURL= sURL; o+?Ko=vYw
sFilePath = sPath; ,62BZyT,T,
sFileName = sName; h|ja67VG
this.nSplitter = nSpiltter; D66!C{
P> ~Lx
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} qb5IpI{U
b<KKF'
L'a>D
public String getSSiteURL() F=yE>[! LB
{ 2_){4+,fu
return sSiteURL; op|x~Thf
} ^7C,GaDsn
2^&5D,}0
yj9Ad*.
public void setSSiteURL(String value) T4}q%%7l
{ VM"*@T
sSiteURL = value; LY!.u?D`P
} 5fK<DkB$>:
:#UN^"(m}
66cPoG
public String getSFilePath() r-o6I:y
{ \fL:Ie
return sFilePath; *. ; }v@
} RTTEAh:.
el,n5OZ7
RQ[6svfP
public void setSFilePath(String value) D]d2opBLj
{ }pv<<7}|
sFilePath = value; ,y/N^^\
} ~ph>?xuw
z#sSLE.$Z
tNCKL.yU
public String getSFileName() l # F.S5i
{ U+g<lgH1J
return sFileName; 3/2G~$C
} p\M\mK
(+0yZ7AZ
7(KVA1P66
public void setSFileName(String value) >]WQ1E[=
{ )rv<"
sFileName = value; ^ZO3:"t!w
} Sc&p*G
NeY,Of|
04R-}
public int getNSplitter() \+sP<'~M
{ k%lz%r
return nSplitter; GG[$-
} X.!|#FWb+
XxE>KeP
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public void setNSplitter(int nCount) p*(]8pDC
{ SiSxym
nSplitter = nCount; kc70HrG
} 7 {#^zr
} .(2ui~ed
Md,KW#
4 g^oy^~
/* Ndr4e?Xa,
**Utility.java mmrz:_
*/ 8?&u5
package NetFox; ?AJE*=b
F^|4nBd*ub
au 5qbP
public class Utility { FrryZe=
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public Utility() vS'5Lm
{ itW~2#nJz
u|]`gsFZ\
o2M4?}TpIV
} o>Jr6:D(
rfS kQT
//线程睡眠 !o&b:7
public static void sleep(int nSecond) F[5\ x0
{ !c8hER!
try{ !*l5%H
Thread.sleep(nSecond); CERT`W%o
} csay\Q{
catch(Exception e) OwM.N+z#T
{ OJF41Z
e.printStackTrace (); nJ-U*yz
} KnuQ5\y
} h^$c
Xm!;
//日志 =Wj{J.7mf]
public static void log(String sMsg) rVo?I
{ 5b^`M
System.err.println(sMsg); fer~NlX
} oCftI':@
)2jBhT
c={bunnz#
public static void log(int sMsg) !DUC#)F
{ Iq[Z5k(K
System.err.println(sMsg); >1n[Y- r
} cc^[u+
} ~'9>jpnw
RIO4`,
$M=W`E[g
/* ZNEWUt{+;^
**TestMethod.java u`2[V4=L
*/ .\X;VWTI
package NetFox; fmhqm"
PV_q=70%T
F};G&
public class TestMethod { <) `?s
BcvCm+.S:
'sCj|=y2Qc
public TestMethod() ZRd,V~iz
{ ///xx/weblogic60b2_win.exe Y@Zv52,
try{ &m>sGCZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5/),HGxi
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); voHFU#Z$
SiteFileFetch fileFetch = new SiteFileFetch(bean); WI$MT6
fileFetch.start(); 1/H9(2{L
} k7gm)}RKcu
catch(Exception e){e.printStackTrace ();} ?Hd/!I&
I;<aJo6Yl
LT3ViCZ-n
} 6HW8mXQh<h
/bd1Bi
#H@rb
public static void main(String[] args) C;6Nu W
{ @l:o0(!W
new TestMethod(); 9"H]zfW
} pUz;e#J|
} ;L gxL Qy;
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