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)); Lo[;{A$u
} ='Oxy
for(int i=0;i<nEndPos.length-1;i++) (Ww SisC~
{ 92,@tNQQ}
nEndPos = nStartPos[i+1]; (ux9"r^g;x
} ga1b%5]v.
nEndPos[nEndPos.length-1] = nFileLength; ZS3T1 <z
} o+^e+ptc
} +N~{6*@uz,
^LSD_R^N
\ X6y".|-
//启动子线程 zuJ` 704
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; GXv2B%i8
for(int i=0;i<nStartPos.length;i++) h52+f
{ - 3<&sTR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Cx) N;x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h4slQq~K
nStartPos,nEndPos,i); )=N.z6?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h_Er$ZT64
fileSplitterFetch.start(); >9g^-~X;v
} RHu,t5,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z&qOu8Jh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ra~:O\Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", el^<M,7!
nEndPos = " + nFileLength); e [F33%
// fileSplitterFetch[nPos.length-1].start(); G0r(xP?
,5sv;
{5fq4AA6
//等待子线程结束 w6B`_Z'f
//int count = 0; iVqF]2>
//是否结束while循环 a}Jy o!.
boolean breakWhile = false; KA`)dMWL
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;ZrFy=Iv
while(!bStop) 5kv]k?
{ q 7+|U%!9
write_nPos(); yg4ILL
Utility.sleep(500); P_@ty~u
breakWhile = true; M?$tHA~OX
52 DSKL
.9!&x0;
for(int i=0;i<nStartPos.length;i++) *EtC4sP
{ 6>EoU-YX}l
if(!fileSplitterFetch.bDownOver) =\<!kJ\yH
{ OBPiLCq
breakWhile = false; twTRw:.!f
break; cja-MljD
} lo>:S1
} 4MgG]
if(breakWhile) }M\G
break; wK%x|%R[
/z(s1G.
69C ss'
//count++; qkyYt#4E
//if(count>4) u-dF~.x
// siteStop(); E~Y%x/oX
} {O[ !*+O
1`n ZK$
A5dH*< }
System.err.println("文件下载结束！"); gm&O-N"=U
} iB'g7&,L
catch(Exception e){e.printStackTrace ();} O{G $]FtF
} k1WyV_3
]0p*EB=C*
23UXOY0BW
//获得文件长度 -| t|w:&
public long getFileSize() v-Uz,3
{ bNz2Uo!0K
int nFileLength = -1; _ID =]NJ_
try{ /^Lo@672
URL url = new URL(siteInfoBean.getSSiteURL()); E!>l@ ki
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6HR*)*>z_
httpConnection.setRequestProperty("User-Agent","NetFox"); ]h&?^L<.
&[}5yos r
O`(it%Ho!
int responseCode=httpConnection.getResponseCode(); Jc9^Hyqu&
if(responseCode>=400) $2*&\/;-E!
{ SB!m&;Tb
processErrorCode(responseCode); L2y{\<JC"
return -2; //-2 represent access is error mZ t:
} C;!h4l7L
P~*v}A
<Xj ,>2m;
String sHeader; AqP\g k
l_*:StyR+
X`n*M]
for(int i=1;;i++) g.O? 1bebe
{ v&ZI<Xt+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9!6yo
//Utility.log(in.readLine()); @sb00ad2q
sHeader=httpConnection.getHeaderFieldKey(i); /B9jmvj`
if(sHeader!=null) QWxl$%`89<
{ u&Dd9kMz
if(sHeader.equals("Content-Length")) !' @
{ 4K*DEVS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CU(W0D
break; s((_^yf
} ?GGh )";y
} nnO@$T
else g|l|)T.s
break; +^.Q%b0Xx
} /T2f~1R
} x?Oc<CQ-2
catch(IOException e){e.printStackTrace ();} (G6N@>V(`
catch(Exception e){e.printStackTrace ();} TMQu'<?V
^l/$ 13=
}u7&SU
Utility.log(nFileLength); UwxrYouv~@
6Bm2_B
#3u471bp
return nFileLength; -x1O|q69
} C!" .[3
4.mbW
C(*)7| m
//保存下载信息（文件指针位置） A,s .<TG
private void write_nPos() x5Ee'G(
{ T)B1V,2j=
try{ 8M'6Kcr
output = new DataOutputStream(new FileOutputStream(tmpFile)); pBu~($%d
output.writeInt(nStartPos.length); DV~1gr,\
for(int i=0;i<nStartPos.length;i++) 4==LtEp
{ \ow0Y>
// output.writeLong(nPos); #TSLgV'U
output.writeLong(fileSplitterFetch.nStartPos); KGX?\#-
output.writeLong(fileSplitterFetch.nEndPos); U!x\oLP
} =<[ZFO~v
output.close(); p{Gg,.f!HM
} s2ys>2k
catch(IOException e){e.printStackTrace ();} WH$ Ls('
catch(Exception e){e.printStackTrace ();} ^5~[G%G4
} S.OGLLprp
$T0|zPK5
[%8+Fa~Wa
//读取保存的下载信息（文件指针位置） "]`QQT-{0
private void read_nPos() ^i^S1h"
{ 2={ g'k(
try{ d|sI>6jD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); BPd]L=,/
int nCount = input.readInt(); r4qFEFV3%
nStartPos = new long[nCount]; 8)k.lPoo.
nEndPos = new long[nCount]; 3?uP$(l
for(int i=0;i<nStartPos.length;i++) T't^pO-`
{ v+=_
nStartPos = input.readLong(); 4.dMNqU
nEndPos = input.readLong(); XfT6,h7vFL
} L3~E*\cV
input.close(); .ODtduURe
} Cst>'g-yB
catch(IOException e){e.printStackTrace ();} }J$PO*Q@'
catch(Exception e){e.printStackTrace ();} QrPWS-3~!
} OkO"t
fwQ%mU+
)V}u1C-N
private void processErrorCode(int nErrorCode) &4DV]9+g
{ h OboM3_
System.err.println("Error Code : " + nErrorCode); qwaw\vOA
} 4p~:(U[q
LVLh&9
j{P,(-
//停止文件下载 :7!/FBd
public void siteStop() (|5g`JDG
{ q#Qr@Jf
bStop = true; Gf'V68,l$
for(int i=0;i<nStartPos.length;i++) xI~\15PhG
fileSplitterFetch.splitterStop(); uj/le0
ZcO!cR&*'J
Qzh:*O
} R/O_*XY
} %r!
//负责部分文件的抓取 T+4Musu{V
**FileSplitterFetch.java >)pwmIn<
*/ Gz@%UIv
package NetFox; \aUbBa%!
dYV)lMJ*
+uwjZN'9a
import java.io.*; "rjJ"u1
import java.net.*; -RH ?FJ
=C\S6bF%
\^-3)*r
public class FileSplitterFetch extends Thread { ?\#4`9
bt&vik _
Hab9~v ]
String sURL; //File URL );|~4#
long nStartPos; //File Snippet Start Position [bT@Y:X@`
long nEndPos; //File Snippet End Position <qRw! 'S^
int nThreadID; //Thread's ID up2%QbN(
boolean bDownOver = false; //Downing is over ^LC5orO
boolean bStop = false; //Stop identical .(1$Q6yG
FileAccessI fileAccessI = null; //File Access interface {2:H`|x
%r!#
|k+&weuY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T8hQ< \g
{ BkqIfV%O
this.sURL = sURL; ln=zGX.e
this.nStartPos = nStart; nQ(#'9
this.nEndPos = nEnd; oG*lUh}
nThreadID = id; Iwn@%?7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mc$c!Ax*
} *BO4"3Z
3P\I;xM
b]g.>$[nX
public void run() @e0Q+t
{ $0W0+A$
while(nStartPos < nEndPos && !bStop) 'b^:"\t'Rh
{ Io"=X!k
UU ,)z
Y+=@5+G
try{ (wY%$kW4
URL url = new URL(sURL); [X~X?By>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7e=a D~f
httpConnection.setRequestProperty("User-Agent","NetFox"); \qTn"1bQ
String sProperty = "bytes="+nStartPos+"-"; 7R2)Klt
httpConnection.setRequestProperty("RANGE",sProperty); 9vj:=,TNu
Utility.log(sProperty); R&alq
X)&Z{ V>
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InputStream input = httpConnection.getInputStream(); Z?Q2ed*j
//logResponseHead(httpConnection); Ph%s.YAZ~
Dps{[3Y+
TwhK>HN
byte[] b = new byte[1024]; 8\V-aow
int nRead; ^LcI6h
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) YI|Gpq
{ ?\pE#~m
nStartPos += fileAccessI.write(b,0,nRead); Y3zO7*-@
//if(nThreadID == 1) ;_SS3q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1Ev+':%
} +|8Lt[^ux
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D!sSe|sL^
Utility.log("Thread " + nThreadID + " is over!"); 8|tm`r`*Az
bDownOver = true; JWn{nJ$]
//nPos = fileAccessI.write (b,0,nRead); QJE-$ :
} !S-hv1bE
catch(Exception e){e.printStackTrace ();} }-Ma~/
} dDuA%V0
} 6b8Klrar!
pnG8c<
-*Pt781
//打印回应的头信息 eS=k 48'U
public void logResponseHead(HttpURLConnection con) J-ZM1HoB
{ i|O7nB@
for(int i=1;;i++) i;xMf5Jz
{ =*Yc/
String header=con.getHeaderFieldKey(i); G7202(w <
if(header!=null) 7r<>^j'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); w${=dW@K
Utility.log(header+" : "+con.getHeaderField(header)); C/vLEpP{(/
else jlP7'xt1%
break; ,qHG1#^
} ).S<{zm7
} y,>m#6hx#
>V$#Um?AXj
)/AvWDKvO
public void splitterStop() Iq=B]oE
{ 8WGM%n#q
bStop = true; :V2Q n-N
} S- \lN|
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_Kj.
} 9C 05
//,'oh~W
<`*P/V
/* #]N9/Hij#g
**FileAccess.java ^k(eRs;K
*//文件访问(定位，写) . R}y"O\
package NetFox; bLzuaNa'
import java.io.*; }"x*xN
oMe]dK
%Eh%mMb^
public class FileAccessI implements Serializable{ u_"h/)C'H
-YyH"f
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 r97[!y1gt
RandomAccessFile oSavedFile; Y fA\#N0;3
long nPos; X&~Eo
p4EItRZS
M\6`2q
public FileAccessI() throws IOException gc~h!%'.I
{ uPXqTkod
this("",0); &s;^q
} 7qz-RF#s8
N8q Z{CWn
~?5m5z O
public FileAccessI(String sName,long nPos) throws IOException Ve1] ECk
{ ')-(N um
oSavedFile = new RandomAccessFile(sName,"rw"); EM/+1 _u
this.nPos = nPos; z{0;%E
oSavedFile.seek(nPos); l,L=VDEz,
} \>`$x:
Av>j+O ;
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public synchronized int write(byte[] b,int nStart,int nLen) e:D"_B
{ vxT"BvN
int n = -1; DOIWhd5:
try{ -\$cGIL
oSavedFile.write(b,nStart,nLen); RbM~E~$
n = nLen; $)]FCuv
} gVJ#LJ
catch(IOException e) z]|[VM?4L
{ UeMe4$m
e.printStackTrace (); Kn$1W=B1.
} ] *VF Ws
3a}`xCO5
mZVOf~9E
return n; 51ebE`
} U(=9&c@]
O9X:1>a@i
D>e\OfTR:
} l1Q+hz5"*U
5l/l]
<^_Vl8%
/* 6CmFmc,
**SiteInfoBean.java # pB:LPEsK
*/ =DTOI
package NetFox; e=UVsYNx
cloSJmUlQ
e@-Mlq)
public class SiteInfoBean { {/xs9.8:JX
TK/'=8
W.D3$
private String sSiteURL; //Site's URL `A _8nW)
private String sFilePath; //Saved File's Path ,Z7Z!.TY!
private String sFileName; //Saved File's Name @dCPa7:>&
private int nSplitter; //Count of Splited Downloading File _xgVuJ
,1;8DfVZV
+Cg"2~
public SiteInfoBean() G=5t5[KC
{//nSplitter的缺省值为5 +Z<Q^5w@
//default value of nSplitter is 5 j~*Z7iu
this("","","",5); LA`VqJ
} [ky6E*dV`
{3(.c, q@
Z;~[@7`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9Y%?)t.2
{ zHOE.V2Qo
sSiteURL= sURL; HU[nN*
sFilePath = sPath; ou^nzm
sFileName = sName; n_n|^4w
this.nSplitter = nSpiltter; ]z=Vc#+!
?g;ZbD
lJzy)ne
} ^%%5
>-@ U_p
CCh8?sM
public String getSSiteURL() Y0B1xL@
{ m?VRX.>
return sSiteURL; YATdGLTeq
} 9N D+w6"
2ZG1n#
_|
public void setSSiteURL(String value) GP[r^Z
{ ,;iBeqr5
sSiteURL = value; @fH&(@
} ](=wlq)
4JZHjf0M6
AMD?LjY~
public String getSFilePath() ki~y@@3I
{ rt^45~
return sFilePath; {rvbo1t
} t0J5v;
VHT@s7u0"
/uE^H%9h
public void setSFilePath(String value) [)SR$/A
{ 2>}\XKF).
sFilePath = value; xOL)Pjo/m
} 8q?;Hg
fQ36Hd?(5
<@e+-$
public String getSFileName() |[37:m
{ /Fo/_=FE2
return sFileName; C. Ja;RFq
} O GFE*
2yQ}Lxr(
y2#>c*
public void setSFileName(String value) E!I
{ {y^|ET7
sFileName = value; )jk1S
} .FKJyzL
xEiX<lguyN
=`1m-
public int getNSplitter() -N7xO)
{ k?HrD"k"
return nSplitter; }PFt
} &=-e`=qJ'6
fNqmTRu
7SK3
public void setNSplitter(int nCount) 9fuJJ3L[
{ .IH@_iX
nSplitter = nCount; wt}%2x} x
} MxgLztY
} Sn(l$wk=
#A3v]'7B
~n/Aq*
/* *vRI)>wU
**Utility.java J`r,_)J"2
*/ {,Bb"0 \
package NetFox; L-z;:Ztk
\oB'
M20Bc,VI
public class Utility { 6)wy^a|pb
i-k >U}[%
t$K@%yU2
public Utility() SH vaV[C
{ ;vJ\]T ml
_V& !4Zd9:
Ns2,hQFc
} m4"N+_j
$U>/i@D
//线程睡眠 _hy{F%}
public static void sleep(int nSecond) ut$,?k!M
{ Hwp{<
try{ (LRM~5KVg
Thread.sleep(nSecond); 7$ =Y\P
} ~{4n}*
catch(Exception e) PUP"ky^q"
{ qX5yN| A4
e.printStackTrace (); ;}/U+`=D?
} fVDDYo2\
} %AG1oWWc>.
#v4LoNm
//日志 *K(k Kph
public static void log(String sMsg) +}^|dkc
{ W|25t)cJ8h
System.err.println(sMsg); z.3<{-n}0i
} ;8ET!&k*>E
?< cM^$lI>
^kn^CI6
public static void log(int sMsg) s.yq}Q
{ u^Nxvx3l0
System.err.println(sMsg); jg [H}
} D<U 9m3
} bmOqeUgB
OXHvT/L`
C$<"w,
/* VEj$^bpp5s
**TestMethod.java S]&8St
*/ J7BFk ?=
package NetFox; ryxYcEM0
+T0op4
0#oBXu
public class TestMethod { sM9FE{,mx
@Od^k#
bMN@H\Ek
public TestMethod() /!GKh5|
{ ///xx/weblogic60b2_win.exe 7%}ay
try{ *Jvxs R'a1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); FR x6c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E *F*nd]K
SiteFileFetch fileFetch = new SiteFileFetch(bean); w6T[hZ 9
fileFetch.start(); &{%MjKJ._
} Ia629gi5s
catch(Exception e){e.printStackTrace ();} :qKF58W
}q%jO
2_;]
} HH)"]E5
9W!8gCs
9!9> ?Z
public static void main(String[] args) EM=w?T
{ 0YzsA#yv
new TestMethod(); ^Q0&.hL@
} ]3*P:$Rq
} ha*X6R
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