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)); 6'qs=Ql
} z` gR*+
for(int i=0;i<nEndPos.length-1;i++) B3I< $
{ T_\GvSOI
nEndPos = nStartPos[i+1]; T}4RlIZF
} nnr(\r~
nEndPos[nEndPos.length-1] = nFileLength; Qz/=+A/4
} <PfW
} '<XG@L
n*_FC
ri\r%x
//启动子线程 {},GxrQm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Kq.)5%~>
for(int i=0;i<nStartPos.length;i++) !FO||z(vb
{ sq :ff
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y;Dw%m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tSQ>P -O
nStartPos,nEndPos,i); FQ O6w'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 53l9s<bOQ
fileSplitterFetch.start(); :r#FI".qx
} a2p<HW;)m
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5ue{&z @T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 81aY*\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^Z}INUv]7
nEndPos = " + nFileLength); iL5+Uf)E3
// fileSplitterFetch[nPos.length-1].start(); seq S*^7
nk6xavQji
r[~Km5
//等待子线程结束 NCl={O9<j
//int count = 0; .Olq_wuH
//是否结束while循环 >eJk)qM
boolean breakWhile = false; >gVR5o
srC'!I=s>8
0!!pNK%(
while(!bStop) JO1c9NyKr
{ .\1XR
write_nPos(); xT=|Uc0
Utility.sleep(500); w3yI;P
breakWhile = true; Vl'|l)b4W
BBy/bc!
B23R9.FK
for(int i=0;i<nStartPos.length;i++) *a+~bX)18
{ )7J@A%u
if(!fileSplitterFetch.bDownOver) SDJAk&Z}R
{ `Jz"rh-M
breakWhile = false; 9~>;sjJk
break; S W
} ZRcY; ?
} }vcC4 =t/
if(breakWhile) /<y-pFTg
break; cty.)e=
nc&V59*
FtE%<QHt
//count++; +B*ygv:
//if(count>4) WvN5IHo 8i
// siteStop(); <PJwBA%{
} mqtl0P0
kS+*@o
WFLT[j!1
System.err.println("文件下载结束！"); [l'~>
} PsLuyGR.<
catch(Exception e){e.printStackTrace ();} 6C) G
} +h[$\_y
5H?`a7q N
%.[GR
//获得文件长度 KWhw@y-5j@
public long getFileSize() eGnc6)x@C
{ +mV4Ty
int nFileLength = -1; ks'25tv}F
try{ R+, tn,<<
URL url = new URL(siteInfoBean.getSSiteURL()); v#D9yttO{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SAXjB;VH6
httpConnection.setRequestProperty("User-Agent","NetFox"); f'R^MX2
~@L$}Eu
_X;5ORH"
int responseCode=httpConnection.getResponseCode(); W^al`lg+y
if(responseCode>=400) $Ne#F+M9x
{ e 0!a &w
processErrorCode(responseCode); k(hes3JV
return -2; //-2 represent access is error N6yqA)z?;
} {f)",#
{P-KU RQ
blxH`O!
String sHeader; -Z]?v3 9
sa*]q~a
/koNcpJ
for(int i=1;;i++) 'du:Bxl`d4
{ (q3(bH~T)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); I)DLnnQQ
//Utility.log(in.readLine()); j3z&0sc2(0
sHeader=httpConnection.getHeaderFieldKey(i); o_os;
if(sHeader!=null) &|Z:8]'P
{ vZ$uD,@;.
if(sHeader.equals("Content-Length")) _0^<)OSY
{ 8|V6RgA%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [#uX{!q'
break; 3]<$;[Q
} 0(-'L\<>x
} >iWl-hI-
else Wc03Sv&FZ
break; 0>Ecm#
} <;SMczR
} 3}n=od=
catch(IOException e){e.printStackTrace ();} WynHcxC
catch(Exception e){e.printStackTrace ();} H6rWb6i
a*74FVZo.;
0XL x@FYn
Utility.log(nFileLength); PS(9?rX#+
]@M$.msg@
<E6]8SQE
return nFileLength; b*r1Jn"h
} :NS;y-{^^y
MdZ7Yep
nN/v7^^
//保存下载信息（文件指针位置） GeZwbJ/?B
private void write_nPos() A$fd6+{
{ 6$@Pk<w
try{ )!p=0&z@{
output = new DataOutputStream(new FileOutputStream(tmpFile)); <k/'mBDk
output.writeInt(nStartPos.length); u|9^tHT>
for(int i=0;i<nStartPos.length;i++) rWi9'6
{ az0( 54M
// output.writeLong(nPos); !tHqF
output.writeLong(fileSplitterFetch.nStartPos); ObMsncn
output.writeLong(fileSplitterFetch.nEndPos); 1wqCoDgkp
} 8uS1HE\%
output.close(); NzNAhlXj3
} K'N\"Y?>
catch(IOException e){e.printStackTrace ();} Yy>%dL
catch(Exception e){e.printStackTrace ();} JL2IVENWc
} duV|'ntr
@+B .<@V
C6CX{IA]
//读取保存的下载信息（文件指针位置） GAtK1%nPD
private void read_nPos() :#c?`>uV
{ {HvR24#
try{ Af ^6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8+v6%,K2
int nCount = input.readInt(); {Kd9}CDAZ
nStartPos = new long[nCount]; Z(*nZT,
nEndPos = new long[nCount]; -:cS}I
for(int i=0;i<nStartPos.length;i++) fC]+C(*d
{ 6DR@$fpt
nStartPos = input.readLong(); _(J- MCY\
nEndPos = input.readLong(); hFj.d]S
} j$&k;S
input.close(); VH+^G)^)W
} *Rr,ii
catch(IOException e){e.printStackTrace ();} !0*=z~
catch(Exception e){e.printStackTrace ();} =EsKFt"
} ^*%p]r
KW^s~j
VlXIM,
private void processErrorCode(int nErrorCode) m{(D*Vuqd
{ ldanM>5
System.err.println("Error Code : " + nErrorCode); DU]MMR
} G\Toi98d*
zZki9P
u%VO'}Gz
//停止文件下载 f![x7D$
public void siteStop() \*!g0C8 o
{ "{qhk{
bStop = true; 1Qhx$If~
for(int i=0;i<nStartPos.length;i++) ;oWhTj`
fileSplitterFetch.splitterStop(); ZUAWSJ,s
sB-c'`,w`
n*@^c$&P
} /o+, =7hY
} _BtppQIWv
//负责部分文件的抓取 >:Xzv
**FileSplitterFetch.java /$&~0pk
*/ cJj0`@0f
package NetFox; 7+#^:;19`
</:f-J%U/
!ny;YV
import java.io.*; A}OV>yM
import java.net.*; %w/o#*j<;
>^D"%Oj y
kh^AH6{2
public class FileSplitterFetch extends Thread { qSkt }F%'
p^5B_r:
xm/v:hl=
String sURL; //File URL }@SZ!-t%rD
long nStartPos; //File Snippet Start Position .Z'CqBr[:
long nEndPos; //File Snippet End Position 6"-LGK:
int nThreadID; //Thread's ID -NiFO
boolean bDownOver = false; //Downing is over A{y3yH`#h
boolean bStop = false; //Stop identical (@uQ>dR:
FileAccessI fileAccessI = null; //File Access interface g0cCw2S
Qn[4&nUD
P,CJy|[L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException onG,N1`+
{ (}gF{@sn
this.sURL = sURL; +g7Iu! cA
this.nStartPos = nStart; Q%o
this.nEndPos = nEnd; o@EV>4e y
nThreadID = id; @UkcvhH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vb{&T<
} i,4
JjyQ
{ tim{nV
public void run() j=PQoEtU'<
{ q,QMvUK:
while(nStartPos < nEndPos && !bStop) T/)$}#w0i
{ #s(B,`?N
<W|{zAyv
9]1-J5iO
try{ wb"Jj
URL url = new URL(sURL); fG0rUi(8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @l$cZie
httpConnection.setRequestProperty("User-Agent","NetFox"); +_ K7x5g
String sProperty = "bytes="+nStartPos+"-"; F{bET
httpConnection.setRequestProperty("RANGE",sProperty); @>(l}5U5
Utility.log(sProperty); 1S 0GjR
y 9/27yWB
$hg W>e
InputStream input = httpConnection.getInputStream(); }1N)3~
//logResponseHead(httpConnection); Ds&)0Iwf
=QRLKo#_
pFGdm3pV
byte[] b = new byte[1024]; ;vQ7[Pv.j
int nRead; Gv?3}8Wp
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) d3 fE[/oU
{ wvx N6
nStartPos += fileAccessI.write(b,0,nRead); |~8iNcIS
//if(nThreadID == 1) ~Jp\'P7*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rQj.W6w=
} lv&<kYWY
m#grtmyMrI
,5t.0XqS
Utility.log("Thread " + nThreadID + " is over!"); i\},
bDownOver = true; 6.KR(V
//nPos = fileAccessI.write (b,0,nRead); \hv*`ukF
} YOP=gvZq
catch(Exception e){e.printStackTrace ();} i. `S0
} + 5sTGNG
} 8l+\Qyj
XZZ Ml
UMx>n18;f9
//打印回应的头信息 'n)M0e
public void logResponseHead(HttpURLConnection con) <3Co/.VQd
{ Uu }ai."iB
for(int i=1;;i++) ~WR6rc
{ } Yjic4?
String header=con.getHeaderFieldKey(i); xJ^Gtq Um
if(header!=null) SobK<6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Fg5>CppH
Utility.log(header+" : "+con.getHeaderField(header)); {B\ar+9>
else )q&uvfQ1(
break; )h2wwq0]
} _9\ayR>d
} QOy+T6en
DH)@8)C
l'B`f)
public void splitterStop() QmT]~4PqS
{ NrNbNFfo
bStop = true; %$!}MxUM
} ?G0=\U< o,
1UyI.U]
/G G QO$'
} Ur?a%]
`Qaw]&O
Y;xVB" (
/* $N+a4
**FileAccess.java Le|Ho^h,Y
*//文件访问(定位，写) .QRQvtd.
package NetFox; ran Q_\
import java.io.*; (!W:-|[K\
RfEmkb<9Z
B~caHG1b
public class FileAccessI implements Serializable{ >[O @u4
sW3-JA]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +\\,FO_
RandomAccessFile oSavedFile; |v[{k>7f
long nPos; %89f<F\V
;}=v|Dr&I.
A4Q8^^byY
public FileAccessI() throws IOException 1ncY"S/VO
{ %]r@vjeyd
this("",0); xo7H^!_
} FTtYzKX(bv
iW.8+?Xq&
e@NS=U` <
public FileAccessI(String sName,long nPos) throws IOException 6b6}HO
{ Q$iv27
oSavedFile = new RandomAccessFile(sName,"rw"); )O#>ONm^
this.nPos = nPos; E`u=$~K
oSavedFile.seek(nPos); a}hpcr({?
} J+Q ;'J
2/E3~X7
5?kF'yksR
public synchronized int write(byte[] b,int nStart,int nLen) F1w~f <
{ jiC;*]n
int n = -1; daGGgSbh
try{ C8-4 m68"
oSavedFile.write(b,nStart,nLen); kNd[M =%
n = nLen; \m*?5]m;
} P7 H-Dw
catch(IOException e) mI@E>VCV[
{ st+X~;PX*
e.printStackTrace (); )$#ov-]
} Gv?'R0s
Ac^}wXp
bo0m/hVU
return n; j42U|CuK
} ) e;)9~
`.#e4 FBW
6^if%62l&
} V[HHP_
8ooj)
Qry?h*p+`
/* }AdA? :7A
**SiteInfoBean.java aNn\URR
*/ Y*oT(
package NetFox; w#ha ^4
<*O~?=6p
v8=7
public class SiteInfoBean { u17e
^B)iBfZ
9em?2'ysa
private String sSiteURL; //Site's URL =/_tQR~
private String sFilePath; //Saved File's Path MA9Oi(L)K
private String sFileName; //Saved File's Name ey4RKk,
private int nSplitter; //Count of Splited Downloading File ue?e}hF
%=C49(/K_
>;|~ z\8
public SiteInfoBean() oUXi4lsSc
{//nSplitter的缺省值为5 Hrz#So\#
//default value of nSplitter is 5 GJ1ap^k
this("","","",5); c-1Hxd YD
} 5!GL"
T4H/D^X|
'x'.[=;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Pr|:nJs
{ _wvSLu<q
sSiteURL= sURL; 0M[O(.x
sFilePath = sPath; {[Bo"a>%
sFileName = sName; h%2;B;p]
this.nSplitter = nSpiltter; ,_ zivUU
lt:xN?--A?
3}U {~l!K
} mPhrMcL
R<"fcsU
*RPdU.
public String getSSiteURL() ?\_\pa/+
{ 4$HU=]b6Tf
return sSiteURL; Nd5G-eYI
} f=$w,^)M
2.xA' \M
N*vBu`
public void setSSiteURL(String value) M|HW$8V3_2
{ :K-05$K
sSiteURL = value; U^AywE]
} BYhF?
|$hBYw
0[/GEY@
public String getSFilePath() G&eRhif
{ ?vnO@Bb/a
return sFilePath; `a$c6^a
} nTy8:k']
@e`%'
P@LFX[HtM
public void setSFilePath(String value) S-^:p5{r
{ *wvd[q h
sFilePath = value; CtEpS<*c
} ?%QWpKO7X
[9hslk
n5Coxvy1
public String getSFileName() R]LRgfi9
{ ?2RDd|#
return sFileName; xOKLc!J
} V8C62X
Ci?BJ,
FrKI=8
public void setSFileName(String value) ~g#$'dS
{ E4CyW
sFileName = value; QsO%m
} B4l*]K%
hggP9I:s,
nfj8z@!
public int getNSplitter() z_;:6*l=:
{ 80'!XKSP
return nSplitter; >TKl`O
} ?3duW$`
?W27 h
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public void setNSplitter(int nCount) O4+a[82
{ c[E"
nSplitter = nCount; k <EzYh
} b+4x2{
} /QgU!:e
*v}3So
oe4r_EkYwW
/* QEC4!$L^
**Utility.java S;I>W&U
*/ -ff@W m
package NetFox; ><HHO (74X
)j_Y9`R
[& d"Z2gK
public class Utility { u/ Gk>F
\>G:mMk/
0#/NZO
public Utility() U!TSAg21P
{ crDm2oA~t
J#/L}h;qH
##\ <mFE
} *LZB.84
FD1Z}v!5IJ
//线程睡眠 =O.%)|
public static void sleep(int nSecond) H\PY\O&cP
{ m4m,-}KNi
try{ J ,s9,("
Thread.sleep(nSecond); iVUkM3
} &{R]v/{p]
catch(Exception e) SK]"JSY`
{ f|r+qe
e.printStackTrace (); ,q".d =6
} {F'~1qf
} 5ns.||%k
jE#&u DfI
//日志 YCBcyE}p
public static void log(String sMsg) bT8 ?(Iu
{ \'>8 (i~
System.err.println(sMsg); Rf4}4ixkj
} j@guB:0
d1{%z\u a
ExW3LM9(
public static void log(int sMsg) Vz\?a8qQ<
{ +\ZaVi
System.err.println(sMsg); P.t0o~hoK;
} e.n*IJ_fz
} hgU#2`fS
!xRboPg
U#mrbW
/* &2Q0ii#Aa
**TestMethod.java Y@#rGV>
*/ >39\u&)
package NetFox; V|q`KOF
v-MrurQ4
uJ:SN;
public class TestMethod { },& =r= B
B s{n
Be4n\c.
public TestMethod() p+y2w{{
{ ///xx/weblogic60b2_win.exe D&]dlY@*
try{ D:I6nSoC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); YsBOh{Ml
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "3H?_!A9
SiteFileFetch fileFetch = new SiteFileFetch(bean); wc~k4B9"
fileFetch.start(); ][[\!og
} 9bb5?b/
catch(Exception e){e.printStackTrace ();} L>X39R~
vUD>+*D
6?uo6 I
} lD]/Kx
){M)0,:
bmd3fJb`r
public static void main(String[] args) |Ev VS
{ J69B1Yi
new TestMethod(); yu98d1
} .8~zgpK
} [}1+=Ub
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