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)); #;qdY[v
} z] PSpUd
for(int i=0;i<nEndPos.length-1;i++) Yi+wC}
{ (\hx` Yh=>
nEndPos = nStartPos[i+1]; #crQ1p) \
} 5Y'qaIFR
nEndPos[nEndPos.length-1] = nFileLength; ~f1%8z
} lVR~Bh
} T?soJ]A
?2;&O`x*
ag#S6E^%S
//启动子线程 z.9U}F
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %x{kc3PnO
for(int i=0;i<nStartPos.length;i++) m=A(NKZ
{ )c83/= <v
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .4M.y:F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), i,E{f
nStartPos,nEndPos,i); NI}yVV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [.'|_l
fileSplitterFetch.start(); \fyRsa)
} nE&@Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _jI,)sr4ic
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); '4Ixqb+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", THbh%)Zv+
nEndPos = " + nFileLength); B=yqW
// fileSplitterFetch[nPos.length-1].start(); W5lR0)~#*
o"Euwh!!
YEs&
//等待子线程结束 uK#4(eY=W
//int count = 0; *1 ]uH e
//是否结束while循环 3yY}04[9<
boolean breakWhile = false; pV +|o.<C
+0%w ;'9z
HU}7zK2
while(!bStop) _ Yx]_Y9I
{ YTX,cj#D^&
write_nPos(); +EAsW(F1
Utility.sleep(500); @ ZwvBH
breakWhile = true; =wHVsdNCN
Zq|I,l0+E
t#/YN.@r
for(int i=0;i<nStartPos.length;i++) eV"h0_ox
{ _AYK435>N
if(!fileSplitterFetch.bDownOver) *@r/5pM2}
{ ,I$`-$_'
breakWhile = false; vNY{j7l/W
break; # E^1|:
} y$F'(b|)
} !/*\}\'4
if(breakWhile) #$+*;
break; BB$>h}
d(x\^z
@* jz o
//count++; VimE@Hz
//if(count>4) }wjw:M
// siteStop(); ;Ax }KN7
} fZzoAzfv2
z'U1bMg
[nG<[<0G;
System.err.println("文件下载结束！"); Lpz>>}
} B+VubUPMS
catch(Exception e){e.printStackTrace ();} n;Q7X>-f8`
} /P3 <"?#k
\fr~
V-2(?auZd
//获得文件长度 |t&>5HM
public long getFileSize() 4qh?,^Dq
{ \0I_<
int nFileLength = -1; #n#}s
try{ VUGmi]qd
URL url = new URL(siteInfoBean.getSSiteURL()); ]^'Kd*x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xJvmhN/c
httpConnection.setRequestProperty("User-Agent","NetFox"); L>NL:68yN
9r<J"%*Q
"]x'PI 4J
int responseCode=httpConnection.getResponseCode(); Y%aCMP9j~9
if(responseCode>=400) PfD.:amN7
{ ~i{(<.he
processErrorCode(responseCode); TG?brgW
return -2; //-2 represent access is error e/&{v8Hmb
} ]BZA:dd.G
q[ZTHd.-
0c]/bs{}
String sHeader; vY}g<*
t?&|8SId
\gGW8Q;
for(int i=1;;i++) Z'W=\rl
{ 8.=BaNU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vjCu4+w($Z
//Utility.log(in.readLine()); g\:[ 55;8
sHeader=httpConnection.getHeaderFieldKey(i); O`\;e>!t
if(sHeader!=null) o#gWbAG;]b
{ |\t-g"~sN
if(sHeader.equals("Content-Length")) 7~p@0)''
{ b<ZIWfs
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); PO^ij2eS
break; '<xXK@=KEI
} "ycJ:Xv49
} @4#c&h3
else RFcv^Xf
break; IGQFtO/x
} ) 7@ `ut
} +oML&g-g_
catch(IOException e){e.printStackTrace ();} gp?uHKsM
catch(Exception e){e.printStackTrace ();} @)M9IOR
D|p9qe5%
9};8?mucr
Utility.log(nFileLength); yu|8_<bq
FUb\e-Q=
Y%^w:|f^
return nFileLength; 5yo%$i8I
} k FD;i
)[IC?U:5I
'ya{9EdlT
//保存下载信息（文件指针位置） H;LViP2K*
private void write_nPos() =zPCrEk0
{ 7"x;~X
try{ S Lj!v&'
output = new DataOutputStream(new FileOutputStream(tmpFile)); iByf{I>+
output.writeInt(nStartPos.length); pRpBhm;iJ
for(int i=0;i<nStartPos.length;i++) djG*YM\B
{ KC6.Fr{
// output.writeLong(nPos); }?i0 I
output.writeLong(fileSplitterFetch.nStartPos); `25yE/
output.writeLong(fileSplitterFetch.nEndPos); M h}m;NI
} gO- _
output.close(); pa3{8x{9m
} OLGE!&!>
catch(IOException e){e.printStackTrace ();} 7U"g3a)=
catch(Exception e){e.printStackTrace ();} 2- h{N
} q:0N<$63
783,s_
>T-u~i$s
//读取保存的下载信息（文件指针位置） *n ]GsOOn
private void read_nPos() C2I_%nU Z1
{ p%Vt#?q
try{ &`r-.&Y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); LA5(sp@O
int nCount = input.readInt(); 0i>5<ej,f
nStartPos = new long[nCount]; ()?(I?II
nEndPos = new long[nCount]; FVbb2Y?R
for(int i=0;i<nStartPos.length;i++) ECuH%b^,
{ ^ VyKd
nStartPos = input.readLong(); 1n8/r}q'H
nEndPos = input.readLong(); 9;u@q%;!k
} xm~`7~nFR
input.close(); An0|[uWH
} |SSSH
catch(IOException e){e.printStackTrace ();} 4k1xy##
catch(Exception e){e.printStackTrace ();} J!(<y(l
} G>}255qY
.2t4tb(SUw
L`TLgH&?R
private void processErrorCode(int nErrorCode) U'_Q>k
{ ET*SB
System.err.println("Error Code : " + nErrorCode); Of#u
} ~,Ix0h+H+M
4F:\-O
+3BN}
//停止文件下载 Dml;#'IF3
public void siteStop() V1zmGy
{ Dx?,=~W9
bStop = true; LonxT&"!D
for(int i=0;i<nStartPos.length;i++) Bkc4TO
fileSplitterFetch.splitterStop(); i&fuSk EP
uH^-R_tQ
8dA~\a
} vI>w e
} K5h
//负责部分文件的抓取 *?vCC+c
**FileSplitterFetch.java <n$'voR7]
*/ (%6P0*
package NetFox; %[TR^Th6
RtS+<^2a;
zC!t;*8a
import java.io.*; q?yVR3]M
import java.net.*; (ZZ8L-s
>+1duAC
cV6D<,)
public class FileSplitterFetch extends Thread { ED gag
.`eN8Dl1
T!#GW/?
String sURL; //File URL + &Eqk
long nStartPos; //File Snippet Start Position iYoMO["X
long nEndPos; //File Snippet End Position 7JH6A'&
int nThreadID; //Thread's ID LEdh!</'24
boolean bDownOver = false; //Downing is over ~<bZ1TD
boolean bStop = false; //Stop identical \M^bD4';>
FileAccessI fileAccessI = null; //File Access interface rM%1GPVob
4+8@`f>s
f$$/H>MJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "KpGlY?^
{ H7n>Vx:L-
this.sURL = sURL; Q)h(nbbVak
this.nStartPos = nStart; C1)!f j=
this.nEndPos = nEnd; J ZS:MFA
nThreadID = id; r#a=@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 oG\Vxg*
} 2[W&s&
S,UDezxg
24eLB?H
public void run() Q197mN+0
{ g) jYFfGfH
while(nStartPos < nEndPos && !bStop) 8lrpve
{ :"c*s4
h2R::/2.
8l`*]1.W<
try{ #"~<HG}bR/
URL url = new URL(sURL); Fx.=#bVX7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); } q8ASYNc
httpConnection.setRequestProperty("User-Agent","NetFox"); H.MI5O(Q
String sProperty = "bytes="+nStartPos+"-"; e\L8oOk#r
httpConnection.setRequestProperty("RANGE",sProperty); kxv1Hn"`{E
Utility.log(sProperty); eSq.GtI
R\[e!g*I
sPIn|d
InputStream input = httpConnection.getInputStream(); ;i+jJ4
//logResponseHead(httpConnection); b>ySv
z2GY:<s
=Xr.'(U
byte[] b = new byte[1024]; 1yhDrpm
int nRead; Q~Wqy~tS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s$j,9uRr
{ k<?b(&`J
nStartPos += fileAccessI.write(b,0,nRead); i/Zd8+.n$
//if(nThreadID == 1) -iZ`Y?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3Y$GsN4ln
} Q$"D]!G
FYQS)s
WpvhTX
Utility.log("Thread " + nThreadID + " is over!"); 3bI9Zt#J%&
bDownOver = true; ;$g?T~v7
//nPos = fileAccessI.write (b,0,nRead); p`qgrI`
} 9pfIzs su3
catch(Exception e){e.printStackTrace ();} !4+<<(B=E
} [nq@mc~<
} G3T]`Atf
|[8Th4*n
9\(| D#
//打印回应的头信息 Q3?F(ER@
public void logResponseHead(HttpURLConnection con) p]c%f2E>d
{ ;O,jUiQ
for(int i=1;;i++) hhvyf^o
{ JBZ@'8eqi]
String header=con.getHeaderFieldKey(i); [:*)XeRK
if(header!=null) _+MJ%'>S
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GM<9p_ B
Utility.log(header+" : "+con.getHeaderField(header)); _Fg5A7or
else <#4h}_xA%
break; )4;`^]F
} |R:'\+E
} lyhiFkO iH
R4d=S4i
1o>xEWt:0K
public void splitterStop() )V9bI(v
{ \~wMfP8
bStop = true; 7G],T++N
} alb.g>LNPP
hi[pVk~B)
q5S9C%b
} xgtR6E^k
I%Z
<gBA1oRz
/* &%Tj/Qx
**FileAccess.java Etm?'
*//文件访问(定位，写) PPsE${!
package NetFox; Z3!`J&
import java.io.*; 9gZ$
}ad|g6i`
RG`1en
public class FileAccessI implements Serializable{ FN73+-:n:j
bZV/l4TU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %8x#rohP
RandomAccessFile oSavedFile; *{{89E>wC
long nPos; vvOV2n.WD
B>.qd
zx7{U8*`<
public FileAccessI() throws IOException &kw@,];4Z
{ cM7[_*Ot<m
this("",0); rrv%~giU
} WX0tgXl
ct}9i"H#1
Xha..r
public FileAccessI(String sName,long nPos) throws IOException A5w6]:f2
{ gZ1?G-Q
oSavedFile = new RandomAccessFile(sName,"rw"); @=kSo -SX
this.nPos = nPos; lw5`p,`
oSavedFile.seek(nPos); n'w.; q
} PFK '$
WuW^GC{7
g=o4Q< #^y
public synchronized int write(byte[] b,int nStart,int nLen) B7vpsSL
{ @s^-.z
int n = -1; #3d(M
try{ h)nG)|c
oSavedFile.write(b,nStart,nLen); pb=h/8R
n = nLen; 5/z/>D;
} \nqS+on]
catch(IOException e) :eLVC7'
{ 8HdAFRw
e.printStackTrace (); ^sg,\zD 'X
} 7"xd1l?zz
=mmWl9'mJ
^zgo#J5O
return n; ]M'=^32
} N)>ID(}F1
wH6aAV~1
xAP+FWyV
} H 7 ^/q7
@ur+;IK$
c6/=Gq{.
/* P L+sR3bR
**SiteInfoBean.java *4_Bd=5(U
*/ Jpo(Wl
package NetFox; 9Lfv^V0
G9vpt M
K'I#W lg
public class SiteInfoBean { G<;*SYAb
Nl(Foya%)
q6X1P"%.
private String sSiteURL; //Site's URL f'3$9x
private String sFilePath; //Saved File's Path 5+ MS^H
private String sFileName; //Saved File's Name e64^ChCoV
private int nSplitter; //Count of Splited Downloading File Q.c\/&
{T~#?v(
fa2kG&, _
public SiteInfoBean() b*Q&CL
{//nSplitter的缺省值为5 LB?u8>a' I
//default value of nSplitter is 5 jOD?|tK&
this("","","",5); 63x?MY6
} <yg F(
dN[\xVcj
Nu~lsWyRI5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &UlWCOo8
{ 1]/.` ]1
sSiteURL= sURL; j^2j&Ta
sFilePath = sPath; 7W.~
sFileName = sName; 42ivT_H
this.nSplitter = nSpiltter; 3%=~)7cF
"`1bA"E
)IZ~G\Ra'
} {3vNPQJ
l0i^uMS
dzrio-QU~
public String getSSiteURL() _ZkI)o
{ .y:U&Rw4
return sSiteURL; $\y'IQ%
} SGlNKA},A
`%WU8Yv
WVvvI9
public void setSSiteURL(String value) *%@h(js
{ hpL;bM'
sSiteURL = value; 1|-Dj|
} by/jYg)+
i@M[>~
0v$~90)
public String getSFilePath() x0:m-C
{ WaR`Kp+>
return sFilePath; n^6j9FQ7
} y7Df_|Z
WU=59gB+jL
;q6Ki.D
public void setSFilePath(String value) 5(HG|
{ t |A-9^t'!
sFilePath = value; 'u<juFr
} 8StgsM
= 6\^%
pr UM-u8
public String getSFileName() I83<r9
{ t" Z6[XG
return sFileName; Pce;r*9
} ?"g2v-jTK
(+y
Dy8r 9
public void setSFileName(String value) 0T5L_%c
{ OMg<V
sFileName = value; LW_f
} @A^;jk
bYQRBi
9.B KI/
public int getNSplitter() ':m,)G5&
{ 8k1Dj1@0z
return nSplitter; m:o<XK[>
} !6Mo]xh
=k`Cr0aPF
Jd^,]
public void setNSplitter(int nCount) ocS5SB]8
{ H6 HVu |
nSplitter = nCount; FNY8tv*/x
} d;9FB[MmOJ
} XtSkh] #z!
o:P}Wg/NK
{w^+\]tC
/* yx&51G$
**Utility.java Opc ZU{4b
*/ (uZ&V7l
package NetFox; 9b"=9y,
~=RT*>G_
;{tj2m,
public class Utility { V"G*N<q
c*L\_Vx+
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public Utility() n!xt5=xP{
{ )@Yf]qx+Y<
(~wqa 3
fd<:_f]v
} ~T,c"t2
Jx](G>F4f1
//线程睡眠 ``\i58K{e
public static void sleep(int nSecond) n+q!l&&
{ q[W 0 N>
try{ 4UvZ)^r
Thread.sleep(nSecond); _Wq
} pRIhFf
catch(Exception e) KZ ;k)O.Ov
{ ?+W9az]+
e.printStackTrace (); dj7hx"BI
} ADP%QTdqFJ
} Cdu4U}^H
RcM/!,B
//日志 s ;oQS5Y
public static void log(String sMsg) '~[d=fwH
{ W~~7C,!
System.err.println(sMsg); -Rd/Gx
} #W'HR
A1D^a,
+)<wDDC_
public static void log(int sMsg) KgiJUO`PR
{ bg&zo;Ck8T
System.err.println(sMsg); IE&!YP(U(
} aM2l2
} E2@65b$
dWUm\t'#
v7jq@#-
/* D!NQ~'.a=2
**TestMethod.java +HeTtFo{M
*/ |_*O'#jx
package NetFox; 7;sj%U^'l
s(%oTKjt
Z&4&-RCi
public class TestMethod { d + /&?3
{G}.b)9FG
$Ifmc`r1
public TestMethod() TI#''XCB5
{ ///xx/weblogic60b2_win.exe LuSLkLN
try{ 9{}1r2xW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E4W -hq~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *-q"3D`
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^3{TZ=_;|
fileFetch.start(); 9:,\gw>F
} X*39c b(b
catch(Exception e){e.printStackTrace ();} `m>*d!h=
s3O} 6
04'~ta(t
} {u\Mj
j =WST
}YMy6eW4
public static void main(String[] args) e~@[18
{ jJY"{foWV
new TestMethod(); }i`PGx
} [}8|R0KF
} 'u_t<F]b
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