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)); 2elj@EB,M
} F[.IF5_
for(int i=0;i<nEndPos.length-1;i++) 2Y=Q%
{ uHDUuK:Ur
nEndPos = nStartPos[i+1]; m^)\P?M5|
} 6e}T zc\@(
nEndPos[nEndPos.length-1] = nFileLength; A?)(^
} nRX<$OzTV
} td#m>S
+yHzp
+,D82V7S
//启动子线程 WCp[6g&%O
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >S?7-2X
for(int i=0;i<nStartPos.length;i++) kaDn= ={YM
{ : R8+jO
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y92<(ziaX)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >4#\ U!
nStartPos,nEndPos,i); u9+)jN<Yh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mj9]M?]
fileSplitterFetch.start(); .=c@ps
} L;KLmxy#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9@*4^Ks p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -OfAl~ 4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UB%;P-RD
nEndPos = " + nFileLength); \OK}DhY#
// fileSplitterFetch[nPos.length-1].start(); PKs$Q=Ol<|
({!*&DVu
|txzIc.#
//等待子线程结束 '_g*I
//int count = 0; `]Vn[^?D
//是否结束while循环 $,T3vX]<
boolean breakWhile = false; i\MW'b
m :]F&s
er!+QD,EM
while(!bStop) #P1;*m
{ YeF'r.Y
write_nPos(); .+^o{b
Utility.sleep(500); ]d&;QZ#w
breakWhile = true; 3v<9 Z9O
rO1.8KKJ
N=:xyv
for(int i=0;i<nStartPos.length;i++) u)ZZ/|
{ ['0^gN$:e
if(!fileSplitterFetch.bDownOver) } x'o`GuUf
{ +!wkTrV
breakWhile = false; uQW d1>
break; jg3['hTJT
} R"PO@v
} 9Mv4=k^7|4
if(breakWhile) q{)Q ?E
break; %E2C4UbY
.>(qZEF
E95VR?nUg
//count++; ?Ye%k
//if(count>4) ]O+Nl5*
// siteStop(); sF#t{x/sW
} It^_?oiK
/3~}=b
sZU Ao&
System.err.println("文件下载结束！"); tLx8}@X"
} h6(L22Hn
catch(Exception e){e.printStackTrace ();} v8A{q
} QOF'SEq"k
E__A1j*gd
N{zou?+
//获得文件长度 E`uK7 2j
public long getFileSize() /s`xPxvt
{ <NMOs"NB
int nFileLength = -1; UgLJV2M6
try{ mHC36ba
URL url = new URL(siteInfoBean.getSSiteURL()); GJuU?h#:/{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RjX#pb
httpConnection.setRequestProperty("User-Agent","NetFox"); DZ|/#- k
N" oJ3-~
h$fC/Juit
int responseCode=httpConnection.getResponseCode(); |n&EbOmgf
if(responseCode>=400) ^kj%Ekt7
{ ,1e@Y~eZ
processErrorCode(responseCode); >(a/K2$*1
return -2; //-2 represent access is error HLM"dmI
} = G3A}
y|Zj M
2c<phmiK
String sHeader; C/pu]%n@4
^kpu9H
&]/.=J
for(int i=1;;i++) <3Hu(Jx<O
{ iD9hqiX&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); MMUw+jM4
//Utility.log(in.readLine()); #Y<b'7yJ
sHeader=httpConnection.getHeaderFieldKey(i); b~FmX
if(sHeader!=null) aD3Q-a[
{ 5($ '@u
if(sHeader.equals("Content-Length")) N DV_/BI
{ S>p>$m, Q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); DnPV Tp(>
break; cj/FqU"
} nyB~C7zR
} "A9 c]
else cb~m==G
break; \>-%OcYlM
} U z6XQskX
} mCx6$jz
catch(IOException e){e.printStackTrace ();} Ok~\
catch(Exception e){e.printStackTrace ();} zHCz[jlrMq
U=bZy,FT$
7e&%R4{b
Utility.log(nFileLength); v<Ux+-
[t`QV2um
_/!IjB:(70
return nFileLength; c8jq.y v
} u5FlT3hY.
= 8%+$vX
bx<7@
//保存下载信息（文件指针位置） /P|jHK|{
private void write_nPos() FeFH_
{ #VEHyz6P
try{ I2'UC) 0
output = new DataOutputStream(new FileOutputStream(tmpFile)); _sCpyu
output.writeInt(nStartPos.length); -.E<~(fad
for(int i=0;i<nStartPos.length;i++) hw&R.F
{ *l^%7Wrk
// output.writeLong(nPos); 4<&`\<jZ
output.writeLong(fileSplitterFetch.nStartPos); qcfLA~y
output.writeLong(fileSplitterFetch.nEndPos); _#+~#U%5n
} Kq';[Yc
output.close(); s0"1W"7vh
} !(Y23w*
catch(IOException e){e.printStackTrace ();} 9_GR\\
catch(Exception e){e.printStackTrace ();} cv["Ps#;`W
} aNCIh@m~
Ol24A^
,tL<?6_
//读取保存的下载信息（文件指针位置） [?hc.COE
private void read_nPos() o3l_&?^
{ #SRGVa`x
try{ ZOG6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]f q.r
int nCount = input.readInt(); j{9sn,<:
nStartPos = new long[nCount]; /wL}+
nEndPos = new long[nCount]; \6xVIQ& 0
for(int i=0;i<nStartPos.length;i++) v7/qJ9l
{ PQ|kE`'
nStartPos = input.readLong(); }ya9 +?I
nEndPos = input.readLong(); pRj1b^F5y
} D[)g-_3f6<
input.close(); Dw^d!%Ala
} GRb"jF>ut
catch(IOException e){e.printStackTrace ();} o84!$2P+w
catch(Exception e){e.printStackTrace ();} ;p#)z/zZ
} MI@id
T)]5k3{
Pz1pEyuL
private void processErrorCode(int nErrorCode) 2, ` =i
{ Jx@3zl
System.err.println("Error Code : " + nErrorCode); .4~n|d>z
} \0m[Ch}~ey
70L{u+wIy
-lm\~VZT3
//停止文件下载 0p_/eWww-
public void siteStop() nj~1y')
{ C_Y^<
bStop = true; ^~2GhveBV
for(int i=0;i<nStartPos.length;i++) nmVL%66K
fileSplitterFetch.splitterStop(); { CkxUec
<w.W[ak
?*a:f"vQ
} @U(D&_H,K
} J]~LmSh
//负责部分文件的抓取 R$=UJ}>
**FileSplitterFetch.java n=n!Hn
*/ EOjo>w>
package NetFox; k9.2*+vvg
|jniI(
[|\~-6"7N|
import java.io.*; 8|`4D 'Ln
import java.net.*; qde.;Yv9
)G0a72
iU\WV
public class FileSplitterFetch extends Thread { %J?;@ G)r
|?SK.1pW
:~pPB#)nk
String sURL; //File URL m0W5Ogk
long nStartPos; //File Snippet Start Position 1+PLj[;jJ:
long nEndPos; //File Snippet End Position <DCrYt!1}c
int nThreadID; //Thread's ID 37Z:WJ?
boolean bDownOver = false; //Downing is over Y6/'gg'&5
boolean bStop = false; //Stop identical S\ ~Wpf
FileAccessI fileAccessI = null; //File Access interface TDdFuO'}
U&|=dH]-
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^PfFW
{ [Zk|s9
this.sURL = sURL; PWOV~`^;
this.nStartPos = nStart; e7ixi^Q
this.nEndPos = nEnd; G@anY=D\EB
nThreadID = id; )%U&z>^P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9Nglt3J[
} 6)kF!/J
b/ h,qv
:Q=Jn?Gjb
public void run() 1GVJ3VXt
{ 74rz~ZM 5
while(nStartPos < nEndPos && !bStop) e;R5A6|
{ Jeyy Z=
/+ vl({vV
7$+n"Cfm
try{ TGGeTtk=
URL url = new URL(sURL); j8!fzJG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [L8Bgw1
httpConnection.setRequestProperty("User-Agent","NetFox"); _K>cB<+d
String sProperty = "bytes="+nStartPos+"-"; K>9]I97g'
httpConnection.setRequestProperty("RANGE",sProperty); 7M<Ae D%
Utility.log(sProperty); xCD|UC46?X
[XjJsk,
<*~vZT i(
InputStream input = httpConnection.getInputStream(); Qi#%&Jz>f
//logResponseHead(httpConnection); R 28v5
{n=)<w
|_8-3
byte[] b = new byte[1024]; iV[g.sP-
int nRead; !9DqW&8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ' D+h_*H
{ d>eVR
nStartPos += fileAccessI.write(b,0,nRead); CeoK@y=o
//if(nThreadID == 1) "d>{hP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F_U3+J>
} `UL#g![J
"?hEGJ;m"
bWo-( qxq
Utility.log("Thread " + nThreadID + " is over!"); 2c@R!*
bDownOver = true; 5bR;R{:x
//nPos = fileAccessI.write (b,0,nRead); f@Rn&&-
} :f?\ mVS+
catch(Exception e){e.printStackTrace ();} mdR:XuRD"t
} .@ZqCH
} ~xpU<Pd*
hV])\t=yf
G0Smss=K
//打印回应的头信息 E8u:Fgs
public void logResponseHead(HttpURLConnection con) }9 N, +*
{ \1hbCv$Hf
for(int i=1;;i++) u{yENZ^P
{ [ /w{,+U
String header=con.getHeaderFieldKey(i); cHs@1R/-s
if(header!=null) $R%xeih1fz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); pHEhB9_A!
Utility.log(header+" : "+con.getHeaderField(header)); YA O, rh
else Wo2TU!
break; 8i=J(5=
} 2ixg ix
} }BS.OK?
:XEP:8
t&^9o$
public void splitterStop() ]tL9y<
{ nellN}jYsM
bStop = true; ehl){Dd^
} -$J\BkI
#"fBF/Q
N%%2!Z#
} ;ajCnSmR
'{p/F $
j1%o+#df
/* d76k1-m\o
**FileAccess.java l9"0Wu@_x
*//文件访问(定位，写) 3~}G~ t
package NetFox; pw" !iG}
import java.io.*; M.))UKSF
mufi>}
Ikql
public class FileAccessI implements Serializable{ j+"i$ln+s
^EWkJW,Yc
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :#1{c^i%3
RandomAccessFile oSavedFile; z$$ E7i
long nPos; >Lx,<sE
q 9lz
KSnU;B6w>
public FileAccessI() throws IOException J^8(h R
{ :0x,%V74_!
this("",0); A94ZG:
} '=K [3%U
bhDV U(%I6
ma[%,u`
public FileAccessI(String sName,long nPos) throws IOException O*xC}$OOn
{ u9My.u@-*%
oSavedFile = new RandomAccessFile(sName,"rw"); A(G%9'T
this.nPos = nPos; h3D~?Iom
oSavedFile.seek(nPos); \fIGMoy!
} AVf'"~?
UjxEbk5>^
. >[d:0
public synchronized int write(byte[] b,int nStart,int nLen) cih@:=Qy
{ |VxEWU/
int n = -1; VI7f}
try{ )Kkw$aQI"d
oSavedFile.write(b,nStart,nLen); Z&9MtpC+N3
n = nLen; 1$T;u~vg
} k=1([x
catch(IOException e) al/Mgo
{ 9o5W\.A7[D
e.printStackTrace (); %Z9&zmO
} .'N:]G@!
([SrIG>X
\^a(B{
return n; "} =RPc%9
} 2u9O+]EP
n "?It
uyBmGS2
} XCr\Y`,Z@
gv)F`uRWA
mOgsO
/* &AM<H}>
**SiteInfoBean.java 7R9.g6j
*/ qNb|6/DG
package NetFox; fd~a\5%e
+@*}_%^l"
P7ktr?V0a
public class SiteInfoBean { 9D@ $Y54
ML@-@BaN
0qP&hybL[(
private String sSiteURL; //Site's URL OiBDI3,|+
private String sFilePath; //Saved File's Path ms9zp?M
private String sFileName; //Saved File's Name !_EL{/ko
private int nSplitter; //Count of Splited Downloading File W,<L/ZKJ
4Ufx,]
?4>uGaU\
public SiteInfoBean() #=@H-ZuD7
{//nSplitter的缺省值为5 +/ s2;G
//default value of nSplitter is 5 qYpuo D
this("","","",5); M]9oSi
} I#lvaoeN
b^ wWg
R-odc,P=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L(Ww6oj
{ O`Ht|@[6
sSiteURL= sURL; CUJP"u>8M
sFilePath = sPath; :eIPPh|\
sFileName = sName; &XG k
this.nSplitter = nSpiltter; kkWqP20q
w&&uk[Gh/a
S}fU2Wi
} QY14N{]T\p
6x18g(KbP
P$l-p'U-
public String getSSiteURL() C-25\
{ )gM3,gSS
return sSiteURL; WKVoqp}
} jvfVB'Tmr
m ,B,dqT
b _Q:v&
public void setSSiteURL(String value) C\.mv|aW~
{ n =SY66
sSiteURL = value; -^A=U7
} _`RzPIS^
%Xm3m0nsv{
VrG4wLpLs
public String getSFilePath() 8R!3}kx
{ !r=^aa(\
return sFilePath; X`xI~&t_
} MYVUOd,
bpe8 `b(#
b1X.#pz7F
public void setSFilePath(String value) nq'vq]]
{ ?gZJ v
sFilePath = value; a2:Tu
} RX]x3-
G`!ff
_W@SCV)yH
public String getSFileName() 7lP3\7wD@9
{ 3,`.$
return sFileName; ,.# SEv5
} JGmW>mH
M:m-iX
[,GXA)j
public void setSFileName(String value) p) x.Y
{ b0\'JZ
sFileName = value; 8mjP2
} H<$.AC\zn
~&E|;\G
7Pt*V@DHS
public int getNSplitter() 7e,<$PH
{ #xWC(*Ggp
return nSplitter; $Cu/!GA4.>
} *q5'~)W<
]mU,y$IQ
0 O{Y Vk`
public void setNSplitter(int nCount) OtopA)
{ ?nm:e.S+?
nSplitter = nCount; !U02>X
} KR
} )G(6=l*
nMU#g])y)
IBwquw+
/* 0m5Q;|mH
**Utility.java K#"@nVWJ.m
*/ eO,
package NetFox; /)80@
] =Js5
//--r5Q
public class Utility { {$iJYS\
(xU+Y1*g"%
{Y5h*BD>
public Utility() my#qmI
{ Isq3YY
9Ao0$|@b
{GF>HHQb
} ^qpa[6D6x
vOYcS$,^X%
//线程睡眠 .js4)$W^
public static void sleep(int nSecond) -;$+`<%
{ UQ|zSalv,
try{ F"a^`E&
Thread.sleep(nSecond); PVO9KWv**
} *$(=I6b
catch(Exception e) p71%-nV
{ ?o0#h
e.printStackTrace (); dRZor gar
} < %Qw dEO
} >qA5
i_GE9A=h
//日志 VmQ7M4j*
public static void log(String sMsg) f{e*R#+&
{ ADX}
System.err.println(sMsg); XA])<dZ
} 3&*0n^g
rL URP2~
;U<)$5
public static void log(int sMsg) f5a%/1?
{ /x_C
System.err.println(sMsg); DT&[W<oN
} |D^Q}uT
} K. G#[
Y=G *[G#
}wR)p
/* BO\l>\)Ir
**TestMethod.java :Puv8[1i
*/ "sFdrXJ
package NetFox; +!POKr
6,G^iv6H
7>{edNy!,
public class TestMethod { kyJv,!};
wrG*1+r
3Gn2@`GC
public TestMethod() 9BANCW"
{ ///xx/weblogic60b2_win.exe HkvCQH
try{ ~E^EF{h
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gx[#@(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); KHr8\qLH
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1jmhh!,
fileFetch.start(); @6*<Xs =
} y<F$@
catch(Exception e){e.printStackTrace ();} }sy3Mrb
LWbWj ^
MC#bo{Bq3-
} 9r1pdG_C@
E08AZOY&g
c%~'[W04\
public static void main(String[] args) {yyg=AMz
{ C>68$wd>
new TestMethod(); ](_(1
} ,h/0:?R KW
} cb%w,yXw
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