http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); { "$2
} Kpj0IfC,10
for(int i=0;i<nEndPos.length-1;i++) d*q_DV
{ li/O&@g`
nEndPos = nStartPos[i+1]; Q?[k>fu0
} Z~$&h
nEndPos[nEndPos.length-1] = nFileLength; LR9dQ=fHS
} T(ponLh
} $XT&8%|*7
/V&$SRdL*
-qx Z3
//启动子线程 Kj-:'jzW
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ijyj}gpWha
for(int i=0;i<nStartPos.length;i++) nSd?P'PFg
{ X)~JX}-L
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I:mJWe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), F_V~UX1D
nStartPos,nEndPos,i); /xf%Rp4}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3ck;~Ncj<
fileSplitterFetch.start(); ?bN8h)>QQ8
} (VBoZP=W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q v{q:=k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); HC!$Z`}Y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", RJBNY;0
nEndPos = " + nFileLength); H6'xXS
// fileSplitterFetch[nPos.length-1].start(); w="I*7c@
n"_EDb
M%9PVePOe
//等待子线程结束 k}jH
//int count = 0; ~rn82an@G
//是否结束while循环 )G*Hl^Z;4
boolean breakWhile = false; eJ7A.O
o @&#*3<_e
/i^b;?/1
while(!bStop) ZH&%D*a&
{ EZBk;*=B
write_nPos(); c#CX~
Utility.sleep(500); ;[dcbyu@
breakWhile = true; >@TZYdl
!>t|vgW
#a}fI
for(int i=0;i<nStartPos.length;i++) =A=er1~%
{ c*1B*_08
if(!fileSplitterFetch.bDownOver) K6|*-Wo.
{ 'lIT7MK
breakWhile = false; 7CwG(c/5
break; M[TgNWl/[
} %&z9^}Vd[
} ,ci tzh
if(breakWhile) JrCm >0g
break; Fz>J7(Y.j
dc%+f
$!KV]]
//count++; T4\,b
//if(count>4) trgj]|?M
// siteStop(); DSET!F;PG
} LD^V="d
% YU(,83(+
EJZl'CR
System.err.println("文件下载结束！"); e ~*qi&,4
} VN`2bp>5I
catch(Exception e){e.printStackTrace ();} *K m%Vl
} 6 D~b9e
4[+n;OI
-?'u"*#1,
//获得文件长度 m=j7 vb
public long getFileSize() )v ['p
{ uCUQxFp
int nFileLength = -1; ?~u"w OH'
try{ {!6!z,
URL url = new URL(siteInfoBean.getSSiteURL()); qZA?M=NT?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ibpk\a?A{
httpConnection.setRequestProperty("User-Agent","NetFox"); G9}[g)R*
Mx$VAV^\
9\Yj`,i5
int responseCode=httpConnection.getResponseCode(); xPsuDi8u
if(responseCode>=400) htMpL
{ ]km8M^P
processErrorCode(responseCode); H={fY:%
return -2; //-2 represent access is error T#er5WOH
} lR;<6
1 ht4LRFi
\{NeDv{A
String sHeader; >JC.qjA
3-LO
~u}[VP
for(int i=1;;i++) wm@1jLjrQ
{ $WTu7lVV[1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #2x\d
//Utility.log(in.readLine()); ~Bj-n6QDE
sHeader=httpConnection.getHeaderFieldKey(i); \? MuORg
if(sHeader!=null) eFZ`0V0
{ f9OVylm
if(sHeader.equals("Content-Length")) (:E^} &A
{ Jq?ai8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ep?a1&b
break; C{Aeud #5
} u5T\_0
} %2/WyD$U
else mL3'/3-7:V
break; }54\NSj0
} Ct #hl8b:
} #T !YFMh;
catch(IOException e){e.printStackTrace ();} %&e5i
catch(Exception e){e.printStackTrace ();} /Q{Jf+>R>
0jj }jw
Hhfqb"2on
Utility.log(nFileLength); 80:na7$)#
[f- #pew
Cn+TcdHX
return nFileLength; c;(}Ih(#
} ;k!Ej-(
rQ~%SUM7
63F0Za}h
//保存下载信息（文件指针位置） \n+`~< i
private void write_nPos() B>9D@fmzs
{ bjD0y cB[
try{ Xo]FOJ5
output = new DataOutputStream(new FileOutputStream(tmpFile)); d{9jd{ _#G
output.writeInt(nStartPos.length); 7J0PO}N
for(int i=0;i<nStartPos.length;i++) s g6
{ S{fNeK
// output.writeLong(nPos); c3K(mM:
output.writeLong(fileSplitterFetch.nStartPos); E/5w H/
output.writeLong(fileSplitterFetch.nEndPos); T[ mTA>d
} 9J l9\y9
output.close(); G0a UZCw
} @bD,^3U
catch(IOException e){e.printStackTrace ();} dR $@vDm
catch(Exception e){e.printStackTrace ();} {Ivu"<`L3
} ~EX/IIa{
B4U+q|OD#
!aIIjWz]
//读取保存的下载信息（文件指针位置） 5r`g6@
private void read_nPos() ! =|{
{ Udd|.JRd
try{ X*d,z~k%*d
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @0Tm>s
int nCount = input.readInt(); xr.fZMOh4
nStartPos = new long[nCount]; }bjTb!
nEndPos = new long[nCount]; .5_w^4`b
for(int i=0;i<nStartPos.length;i++) 7\5 [lM
{ m#'u;GP]k
nStartPos = input.readLong(); ii{5z;I]X
nEndPos = input.readLong(); ,X9Y/S l
} CX\# |Q8q
input.close(); L(AY)gB
} gIRFqEz@o
catch(IOException e){e.printStackTrace ();} TLO-$>h
catch(Exception e){e.printStackTrace ();} 8G(wYlxi
} ;~xkT'
KA%tVBl
o2F6K*u}
private void processErrorCode(int nErrorCode) coU`2n/
{ zXp{9P\c
System.err.println("Error Code : " + nErrorCode); LH0\SmhU
} 8 I,(\<Xv
"64pVaT4
H:p(C?tk{
//停止文件下载 fa"eyBO50
public void siteStop() E)>6}0P
{ ]$KH78MTW
bStop = true; /5zzzaj{
for(int i=0;i<nStartPos.length;i++) kw?RUt0-V
fileSplitterFetch.splitterStop(); |p3]9H
Rp9uUJ 6o
k6G23p[9
} KHdj#3<AR
} 8Ck:c45v
//负责部分文件的抓取 -OVJ]
**FileSplitterFetch.java }7Pd\tG]
*/ (3=.3[
package NetFox; [wIyW/+
>(d+E\!A
vhKeW(z
import java.io.*; 1~ZDHfd5
import java.net.*; ^c.b@BE
Q_M2!qj
*>Om3[D
public class FileSplitterFetch extends Thread { Z1OX9]##r
[o>/2
pE15[fJ`
String sURL; //File URL M.H4ud
long nStartPos; //File Snippet Start Position ,>"1'i&@
long nEndPos; //File Snippet End Position *4=Fy:R]O
int nThreadID; //Thread's ID Vv6xVX
boolean bDownOver = false; //Downing is over 4}#*M2wb
boolean bStop = false; //Stop identical AF **@iG
FileAccessI fileAccessI = null; //File Access interface wBCnP
f)N67z6
@CWfhc-Ub
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'pZ~3q
{ ~hP[[?
this.sURL = sURL; <}.)kg${O
this.nStartPos = nStart; dk;Ed
this.nEndPos = nEnd; AGOK%[[Ws
nThreadID = id; }2DeqY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 GTJ\APrH
} C,jPr )6)
R)G'ILneV
vWzNsWPK"{
public void run() PMkwY{.u
{ zgVplp
while(nStartPos < nEndPos && !bStop) Og-Mnx3
{ uodO^5"-
`4l>%S8y:
%3"3OOT7
try{ V}@c5)(j
URL url = new URL(sURL); bCA3w%,kM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]:]2f9y
httpConnection.setRequestProperty("User-Agent","NetFox"); )mwY] !
String sProperty = "bytes="+nStartPos+"-"; nef-xxXC^I
httpConnection.setRequestProperty("RANGE",sProperty); uCmdNY
Utility.log(sProperty); 7|65;jm+
lm-ubzJN
v mw7H
InputStream input = httpConnection.getInputStream(); r|0C G^:C
//logResponseHead(httpConnection); Re,0RM\
^!Bpev
,gD30Pylz
byte[] b = new byte[1024]; mX,#|qLf
int nRead; "ZT=[&2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v-OGY[|97
{ $0cMrf@
nStartPos += fileAccessI.write(b,0,nRead); =oiY'}%(i
//if(nThreadID == 1) "P0o)g+{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #v~zf@<KLB
} |!IJ/ivEgw
d5sGt#
BWw7o{d
Utility.log("Thread " + nThreadID + " is over!"); |%zhwDQ.
bDownOver = true; lWnV{/q\X
//nPos = fileAccessI.write (b,0,nRead); TSE(Kt
} C8NbxP
catch(Exception e){e.printStackTrace ();} L\hPw{)
} `1pri0!
} )?Jj#HtW
/?2yo{Fg
%;^6W7
//打印回应的头信息 f\/};a
public void logResponseHead(HttpURLConnection con) 7_q"%xH
{ Uf_w o
for(int i=1;;i++) a ,W5T8
{ "@`M>)*o
String header=con.getHeaderFieldKey(i); 0ZPPt(7
if(header!=null) *4A.R&Vu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `Gsh<.w!7
Utility.log(header+" : "+con.getHeaderField(header)); ^_2Ki
else NW!e@;E+i
break; Km\M/j|
} !M3IuDN
} :!{aey
uiHlaMf
`EWeJ(4Z@
public void splitterStop() )Tb{O
{ b/ZX}<s(1=
bStop = true; S7N54X2JwL
} @,zBZNX y
$o]suF;3
EXb{/4
} %y8w9aGt
zU1rjhv+
j:{<
/* & qd:o}
**FileAccess.java 5zEl`h
*//文件访问(定位，写) W,wg@2
package NetFox; |#!25qAT
import java.io.*; G-,PsXSwe
:5@7z9 >
E*RP8
public class FileAccessI implements Serializable{ xx/DD%IZ
|k?,4 Pk
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [C7:Yg7
RandomAccessFile oSavedFile; .fQDj{
long nPos; TzX>d<x
Vvv -f
}8x[
public FileAccessI() throws IOException A$1pMG~as
{ o"'VI4
this("",0); Or6'5e?N
} 5{cAawU.
qZ8lU
rV2}> k
public FileAccessI(String sName,long nPos) throws IOException n,xK7icYNQ
{ 1l1X1
oSavedFile = new RandomAccessFile(sName,"rw"); vLpE|QZs
this.nPos = nPos; ~(hmiNa;
oSavedFile.seek(nPos); D(Xv shQ
} |mci-ZT
5|H?L@_9
vz@QGgQ9~2
public synchronized int write(byte[] b,int nStart,int nLen) ;5 IS58L
{ X>*zA?:
int n = -1; G.<9K9K
try{ C'zMOR6c
oSavedFile.write(b,nStart,nLen); `=CF |I
n = nLen; -U;s,>\)
} KZD&Ih(vC
catch(IOException e) tK8\Ib J
{ E}"&?oY
e.printStackTrace (); %M'"%Yn@(y
} X}p4yR7'
BAzqdG
lkw[Z}\
return n; Li<c
} k$I[F<f
Dw.>4bA.
B5tJ|3!
} ,ew<T{PL
",~3&wx
EE%OD~u&9#
/* ?$r+#'asd(
**SiteInfoBean.java 3&2,[G04
*/ U][.ioc
package NetFox; bF B;N+>
xn6E f"
hXMC!~Th
public class SiteInfoBean { EaP#~x
+S3'ms
.cu5h
private String sSiteURL; //Site's URL 9N'$Y*. d<
private String sFilePath; //Saved File's Path CQv [Od
private String sFileName; //Saved File's Name -R&h?ec
private int nSplitter; //Count of Splited Downloading File .X:{s,@
[Q^kO;
w)!(@}vd
public SiteInfoBean() \&e+f#!u
{//nSplitter的缺省值为5 HkrNh>^=
//default value of nSplitter is 5 c/g(=F__[
this("","","",5); UejG$JyHP
} B]]M?pS
6j` waK
MJ92S(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6^ /C+zuX
{ }n:-nB4
sSiteURL= sURL; tQwbIX-7/
sFilePath = sPath; *DG*&Me
sFileName = sName; v $pARt
this.nSplitter = nSpiltter; yK}#|b'cM
dC.uK^FuJ
c6?5?_ne
} ` 0\hm`
xRaYm
v`v+M4upC
public String getSSiteURL() ?]P&3UU>0z
{ "BzRLg!J
return sSiteURL; Zr$PSp}
} _$fxoD9
E6@+w.VVO
A\SbuRty
public void setSSiteURL(String value) "%}PVO!
{ I7[+:?2
sSiteURL = value; e?f[t*td
} yGN<.IP75
"CZ`hx1|^
`qfVgT=2
public String getSFilePath() jj.yB#T
{ g5T~%t5lo
return sFilePath; xQmk2S` y
} y XS/3_A{
!Noabt
}4bwLO
public void setSFilePath(String value) Qs,LK(1
{ yLY2_p-X
sFilePath = value; G1P m!CM=
} k@wT,?kD
9Y/c<gbY
:b.#h7Qt<
public String getSFileName() ?rv+ydR/q
{ '!y ^
return sFileName; }>h?W1
} >i=O =w
B!8]\D
[IHT)%>E8&
public void setSFileName(String value) (jQL?
{ *Qyw _Q
sFileName = value; U+'?#" J8(
} vn kktD'n
7p~@S4
2&=;$2?}
public int getNSplitter() ]jy6C'Mp
{ 1x\%VtO>\b
return nSplitter; b"f4}b
} *^NC5=A(d
ls/:/x(5d
TuX#;!p6
public void setNSplitter(int nCount) lSbAZ6
{ S:t7U%
nSplitter = nCount; u`("x5sa
} "+)ey>_
} DE. Pw+5<.
bu$5gGWVf
%GHHnf%2Z
/* #b{otc)
**Utility.java LoTq2/
*/ GLk7#Y
package NetFox; t(ZiQ<A
}~A-ELe:
A70_hhP
public class Utility { .oSKSld
@NV$!FB<
S'?XI@t[
public Utility() Z0-W%W
{ ,a?em'=
Nzr zLK
WM>9sJf
} d;'@4NX5+
w0 "h,{
//线程睡眠 m&; t;&#
public static void sleep(int nSecond) >~ne(n4qy
{ |7f}icXKur
try{ "e(OO/EZS
Thread.sleep(nSecond); ss-Be
} e"2 wXd_}
catch(Exception e) Gq0~&6
{ ,Q}/#/
e.printStackTrace (); 7OW;omT`
} OP<@Xz
} wRLkO/Fw
Kj'm<]u
//日志 Rfgc^3:j
public static void log(String sMsg) VJ1si0vWtq
{ ){gOb
System.err.println(sMsg); (hmasy6hM
} &5zUk++
i5-V$Qh
Q&n|tQ*4
public static void log(int sMsg) iv56zsR
{ KiCZEA
System.err.println(sMsg); 2-{8+*_'
} . vYGJ8(P
} 8n2*z
LkNfcBa_
Mu{mj4Y{
/* (:@qn+ a
**TestMethod.java 2{{M{#}S.
*/ C~6aX/:
package NetFox; f2yc]I<lr~
b7"pm)6
SHhg&~B
public class TestMethod { A #ZaXu/:X
*d(wOl5[
a{]1H4+bQ
public TestMethod() hBN!!a|l
{ ///xx/weblogic60b2_win.exe FJ#V"|}
try{ _|~2i1Ms,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); LsBDfp5/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); drN^-e
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8zZR%fZ
fileFetch.start(); q9!5J2P
} 8mx5K-/,y^
catch(Exception e){e.printStackTrace ();} OPKm^}
)zr/9aV
sRY: 7>eg
} +mAMCM2N
T@k&YJ
t6js@Ih
public static void main(String[] args) :*Ckq~[Hg
{ vA+RZ
new TestMethod(); `W|2Xi=^5
} "7gS*v,r
} ;'cv?3Y
点击下载更多相关资料