http断点续传简单实现（java)

/* 
,v*p  
**SiteFileFetch.java =! N _^cb  
*/ ',sQ/#S  
package NetFox; xvR?~  
import java.io.*; -@SOo"P  
import java.net.*; <TR/ `  
my ;  

ik2- OM  
public class SiteFileFetch extends Thread { +ze}0lrEL  
CF|moc:;  
#
vj#! 1  
SiteInfoBean siteInfoBean = null; //文件信息Bean $ZI~8rI~  
long[] nStartPos; //开始位置 _Z+jQFKJ\8  
long[] nEndPos; //结束位置 \Pl,' 1%  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 S<eZd./p6  
long nFileLength; //文件长度 }X
CR+uAz  
boolean bFirst = true; //是否第一次取文件 q%-&[%l  
boolean bStop = false; //停止标志 .Vo"AuC}  
File tmpFile; //文件下载的临时信息 >f\zCT%cf  
DataOutputStream output; //输出到文件的输出流 -BA"3 S  
fJLf7+q  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） #\pP2  
public SiteFileFetch(SiteInfoBean bean) throws IOException H(15vlOD  
{ cy)k<?,  
siteInfoBean = bean; I9
}+(6  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); :[Qp2Gg O\  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); R}DX(T,K  
if(tmpFile.exists ()) L1hD}J'$4  
{ 'e.q 7Jpd  
bFirst = false; F!7f_m0=  
read_nPos(); g7xbyBo7  
} \|2tTvW,0  
else \6 \hnP  
{ 7qP4B9S  
nStartPos = new long[bean.getNSplitter()]; oGm1d{_-O  
nEndPos = new long[bean.getNSplitter()]; ?R;nL{  
} 3sZ,|,ueD  
/Hv*K&}M  
,b<9?PM  
i8Fs0
U4"  
} 5<89Af&&K8  
^|wT_k\  
2GSgG.%SSM  
public void run() la'e[t7  
{ Z#-k.|}  
//获得文件长度 cz2,",+~  
//分割文件 \Okc5;kB2  
//实例FileSplitterFetch .zvlRt.zl  
//启动FileSplitterFetch线程 f.||PH  
//等待子线程返回 LthGZ|>  
try{ hPan  
if(bFirst) 0VzXDb>`  
{ 9>N\sOh  
nFileLength = getFileSize(); nVxq72o@  
if(nFileLength == -1) $ !v}xY  
{ m!<X8d[bD  
System.err.println("File Length is not known!"); J?Ck4dQ  
} 6nh]*/  
else if(nFileLength == -2) f hQy36i@  
{ NEA_Plt  
System.err.println("File is not access!"); MZT6g.ny  
} a3Y{lc#z}  
else )ZHc$+fU  
{ i{8]'fM  
for(int i=0;i<nStartPos.length;i++) |~SE"  
{ I>{!U$  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); H(G!t`K  
} %a5t15 9  
for(int i=0;i<nEndPos.length-1;i++) tXt:HVN  
{ 7))\'\  
nEndPos = nStartPos[i+1]; -b cG[W3  
} \a"i7Caa  
nEndPos[nEndPos.length-1] = nFileLength; <EtUnj:qK8  
}  ]nUR;8  
} 9#uIC7M  
vYDSu.C@a  
zI:(33)  
//启动子线程 eUt=n)*`  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *B1x`=  
for(int i=0;i<nStartPos.length;i++) "K,bH  
{ f'&GFL=c  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YMT8p\#rp  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^IBGYl5n  
nStartPos,nEndPos,i);
"OO96F  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U^[<  
fileSplitterFetch.start(); %JQ~!3  
} Va7c#P?  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~LbS~_\C=  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); z!$gVWG  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", gmY/STN   
nEndPos = " + nFileLength); a:A n=NA  
// fileSplitterFetch[nPos.length-1].start(); IAf$]Fh  
~\$=w10  
Jen%}\  
//等待子线程结束 PWvSbn6  
//int count = 0; Vvyj  
//是否结束while循环 QC{u|  
boolean breakWhile = false; mzGjRl=O  
G$C}?"l  
;7rd;zJ  
while(!bStop) 5SUN.%y  
{ r} Lb3`'  
write_nPos(); Edw2W8  
Utility.sleep(500); -/>9c-F  
breakWhile = true; b6"}"bG  
T7{<arL$  
cGNvEM(4AV  
for(int i=0;i<nStartPos.length;i++) Q"%S~&#'  
{ qe$33f*  
if(!fileSplitterFetch.bDownOver) j$Nf%V 6Y  
{ (S|a 9#  
breakWhile = false; QdDObqVdy  
break; 9~c~E/4!  
} 1"?]= j:  
} :Hk_8J  
if(breakWhile) /v|Onq1Y4  
break; _1  pDA  
&~ *.CQa  
k#C f})  
//count++; wK ?@.l)u  
//if(count>4) 2ev*CX6.  
// siteStop(); =q+R   
} 1a$IrQE  
H\E7o"m  
Vr/
Bu4V"  
System.err.println("文件下载结束！"); w2{g,A|  
} WULAty  
catch(Exception e){e.printStackTrace ();} =A@>I0(7  
} qZ*f%L(  
+~Tu0?{Z 0  
)JhT1j
Qc  
//获得文件长度 -#.< 12M  
public long getFileSize() d yh<pX/$  
{ :g2  }C  
int nFileLength = -1; (wuaxo:  
try{ *0y{ ~@  
URL url = new URL(siteInfoBean.getSSiteURL()); bO3GVc+S  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *}cSE|S%  
httpConnection.setRequestProperty("User-Agent","NetFox"); R>2IRvY(  
ET:T7
 
$.rzc]s  
int responseCode=httpConnection.getResponseCode(); 5Fbs WW2  
if(responseCode>=400) A&zS'toU  
{ $DebXxJw0l  
processErrorCode(responseCode); gKo%(6{n~  
return -2; //-2 represent access is error O9s?h3  
} Qz,|mo+  
Bz /@c)  
*geN[[  
String sHeader; :,S98
z#  
])w[

  
|=6_ xRyr  
for(int i=1;;i++) r37[)kJ  
{ 8 #}D :(  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %}3qR~;  
//Utility.log(in.readLine()); 8(f
:U@BS  
sHeader=httpConnection.getHeaderFieldKey(i); 6>`c1 \8f  
if(sHeader!=null) +G*JrwJ&=  
{ NHm]`R,  
if(sHeader.equals("Content-Length"))
""% A'TZ  
{ 3qaMO#{
M  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ''H"^oS  
break; SeEw.;Xw  
} sy/nESZs  
} 0uvzxmN  
else f>polxB%N  
break; Kj3?ve~  
} t"vRc4mf  
} $s-Y%gc  
catch(IOException e){e.printStackTrace ();} PuL<^aJ  
catch(Exception e){e.printStackTrace ();} G[,Q95`w?<  
X~oK[Nf'9  
S($Su7g%_  
Utility.log(nFileLength); 0 1V^L}  
Y32 "N[yw  
R=]d%L8  
return nFileLength; F;q#&  
} Kibr ]w  
a5jL7a?6]  
J00
VTb`  
//保存下载信息（文件指针位置） F$V/K&&W  
private void write_nPos() !do?~$Og  
{ +B}0=Ex$t  
try{ #%lo;W~IY  
output = new DataOutputStream(new FileOutputStream(tmpFile)); YA:nOvd@O  
output.writeInt(nStartPos.length); o0bM=njok  
for(int i=0;i<nStartPos.length;i++) BU|#e5  
{ O|kOI?f  
// output.writeLong(nPos); 9?<{_'  
output.writeLong(fileSplitterFetch.nStartPos); aUU7{o_Z  
output.writeLong(fileSplitterFetch.nEndPos); 3g~'5Ao  
} _S}A=hK'  
output.close(); `aC){&
AP(  
} . pzC5Ah  
catch(IOException e){e.printStackTrace ();} #,d I$gY  
catch(Exception e){e.printStackTrace ();} c;2#,m^  
} vBcq_sbo  
Pe;Y1Qq>>  
eE GfM0  
//读取保存的下载信息（文件指针位置） vy9 w$ls  
private void read_nPos() )2IH 5  
{ [ic87
0_  
try{ *Hz^K0:8(  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f+_h !j  
int nCount = input.readInt(); AlXNg!j;5K  
nStartPos = new long[nCount]; J aTp}#  
nEndPos = new long[nCount]; 457\&  
for(int i=0;i<nStartPos.length;i++) kF"@Ngv.  
{ n+;6=1d7ZW  
nStartPos = input.readLong(); 'Ft0Ry<OL  
nEndPos = input.readLong(); U1nw-Q+  
} "VG+1r+]4  
input.close(); 1KM`i  
} ^(HUGl_  
catch(IOException e){e.printStackTrace ();} aJ") <_+  
catch(Exception e){e.printStackTrace ();} ~*A8+@\R  
} 4)|8Eu[p7  
kE9esC3  
!K f#@0E..  
private void processErrorCode(int nErrorCode) xG&)1sT#-\  
{ Gs+3
e8  
System.err.println("Error Code : " + nErrorCode); H,nec<Jp  
} VXLT^iX  
d?`ny#,GB  
aE;le{|!({  
//停止文件下载 scLn=  
public void siteStop() fk1ASV<rN  
{ ojvj}ln  
bStop = true; '(bgs  
for(int i=0;i<nStartPos.length;i++) ?T9(Vw  
fileSplitterFetch.splitterStop(); .sC?7O=  
nD5 gP  
tg]x0#@s  
} 26&'X+n&  
} &0 >Loja`^  
//负责部分文件的抓取 R}^~^#  
**FileSplitterFetch.java 6f')6X'x  
*/ "#[!/\=?:  
package NetFox; )M6w5g  
Q8!)!r%  
S4=~`$eP  
import java.io.*; )OiT{-m  
import java.net.*; 'Vyt4^$%  
o(DOQGl  
I!e})Y  
public class FileSplitterFetch extends Thread { S;$-''o?9  
[<DZ*|+  
KD`IX-r{s  
String sURL; //File URL AC>`'Gx  
long nStartPos; //File Snippet Start Position Oo"^%F~%  
long nEndPos; //File Snippet End Position Ag{iq(X  
int nThreadID; //Thread's ID 0"CG7Vg,zh  
boolean bDownOver = false; //Downing is over ^*P%=>zO  
boolean bStop = false; //Stop identical &|f@$ff  
FileAccessI fileAccessI = null; //File Access interface yKYTi3_(  
Hemq+]6^  
o.0ci+z@  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WI?oSE w  
{ u%w`:v7Yo(  
this.sURL = sURL; nqInb:  
this.nStartPos = nStart; v?KC%  
this.nEndPos = nEnd; \"X!2  
nThreadID = id; bGc~Wr|  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C:PMewn  
} O3I8k\`  
uc;8 K,[t  
n4}Br;%  
public void run() \v'p/G)g  
{ !%"8|)CAr  
while(nStartPos < nEndPos && !bStop) 87D*-Gw  
{ /YZr~|65  

E\Rhz]G(  
x>Zn?YR,"  
try{ b )B?
F  
URL url = new URL(sURL); {q"OM*L(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {NHdyc$  
httpConnection.setRequestProperty("User-Agent","NetFox"); DRcNdO/1E  
String sProperty = "bytes="+nStartPos+"-"; {phNds%  
httpConnection.setRequestProperty("RANGE",sProperty); &*+'>UEe5  
Utility.log(sProperty); `DV.+>O-1  
q@[QjGj@  
Y;?{|  
InputStream input = httpConnection.getInputStream(); _lamn}(x0  
//logResponseHead(httpConnection); /Mvf8v  
!\7!3$w'8,  
eEuvl`&  
byte[] b = new byte[1024]; <StN%2WQ1  
int nRead; .&DhN#EN0  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +j< p \Kn>  
{ ,6-:VIHQ  
nStartPos += fileAccessI.write(b,0,nRead); Wk)OkIFR  
//if(nThreadID == 1) 7@D@ucL  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #"@|f  
} *MKO I'  
OCNQvF~  
G"h'_7  
Utility.log("Thread " + nThreadID + " is over!"); o,_?^'@  
bDownOver = true; < jJ  
//nPos = fileAccessI.write (b,0,nRead); JpXlBEio%  
} hDF@'G8F  
catch(Exception e){e.printStackTrace ();} MF5[lK9e  
} wB.&}p9p  
} 0y
D9SJn  
k?+?v?I =  
.yz}ROmN^  
//打印回应的头信息 E=nIRG|g  
public void logResponseHead(HttpURLConnection con) vSEuk}pk  
{ &L=suDe  
for(int i=1;;i++) As'=tIro  
{ YNQY4\(  
String header=con.getHeaderFieldKey(i); <0Xf9a8>  
if(header!=null) \W~N  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =vX/{C  
Utility.log(header+" : "+con.getHeaderField(header)); gEy?s8_,  
else [CQ+p!QZ  
break; h2G$@8t}I  
} Q+[n91ey**  
} :tV*7S=)  
x(1:s|Uyp{  
Fld=5B^}  
public void splitterStop() AE[b},-[  
{ JRB9rSN^  
bStop = true; VK m&iidU  
} '=b/6@&  
qLD ?juas  
Q'=x|K#xj  
} dYJ(!V&  
y [}.yyye  
IG2r#N|C#  
/* F3On?x)  
**FileAccess.java Te"ioU?.  
*//文件访问(定位，写) k\5c|Wq|g  
package NetFox; ~%&LTX0s|  
import java.io.*; La`NPY_:>  
]Sf]J4eQ  
KcWN,!G  
public class FileAccessI implements Serializable{ m|n  
5?{r  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +^60T$  
RandomAccessFile oSavedFile; TM%|'^)  
long nPos; ]cHgleHQ  
>g1~CEMN#  
q'T4w!V(V  
public FileAccessI() throws IOException ]_f_w9]  
{ marQNZ  
this("",0); hOjk3 k  
} j#!IuH\]  
$V-~Bu-  
gb[5&>(#  
public FileAccessI(String sName,long nPos) throws IOException M?1Y,5  
{ =^M/{51j  
oSavedFile = new RandomAccessFile(sName,"rw"); 6]K_m(F  
this.nPos = nPos; %O|iE M  
oSavedFile.seek(nPos); Ag-
(5:  
} 8\&X2[oAD  
XO.jl"xu  
s
lCx w$  
public synchronized int write(byte[] b,int nStart,int nLen) }Y12  
{ n(1l}TJy  
int n = -1; @LF,O}[2J  
try{ R0KPZv-  
oSavedFile.write(b,nStart,nLen); ?gA 8x  
n = nLen; PxvyN_B#>  
} P)Jgs  
catch(IOException e) L+b6!2O,  
{
X_q\Sg  
e.printStackTrace (); ha]VWt%}  
} f\|w'  
n@<YI  
V'z1  
return n; i1}:8Unxf  
} )1?y 8_B  
f z'@_4hg  
LBw1g<&  
} ^pp\bVh2Q]  
h0g8*HY+}  
KI"#f$2&  
/* l!D}3jD  
**SiteInfoBean.java 01 }D,W`  
*/ hNC&T`.-~B  
package NetFox; g|
o,uD  
qU \w=  
Q*D;U[  
public class SiteInfoBean { qqjwJ!@P  
lU8l}Ndz"  
(p"%O  
private String sSiteURL; //Site's URL 4>wP7`/+y  
private String sFilePath; //Saved File's Path OIGY`   
private String sFileName; //Saved File's Name Ogqj?]2QC  
private int nSplitter; //Count of Splited Downloading File j`{?OYD  
8SMxw~9$  
HY56"LZ$(}  
public SiteInfoBean() zYH&i6nj  
{//nSplitter的缺省值为5 sA+ }TNhq  
//default value of nSplitter is 5 /:cd\A}  
this("","","",5); g@d*\ P)  
} {i;r  
M H|Og84  
#|uCgdi  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )HEa<P^kJl  
{ Ki;*u_4{  
sSiteURL= sURL; xK>*yV  
sFilePath = sPath; 3(>B Ke  
sFileName = sName; )*u8/U  
this.nSplitter = nSpiltter; `}p0VmD{NE  
7y.kQI?3  
iDpSj!x/_  
} mVj9,q0  
* `JYC  
z0d.J1VW  
public String getSSiteURL() /4yo`  
{ sU=H&D99  
return sSiteURL; D(~U6SR  
} " s,1%Ltt  
P9R9(quI  
v&6-a*<Z  
public void setSSiteURL(String value)  {y)=eX9  
{  CT&|QH{  
sSiteURL = value; b!+hH Hv:  
} -M\<nx  
4j-Xi  
l5~os>  
public String getSFilePath() d9k0F OR1  
{ zrvF]|1UP  
return sFilePath; )~X2 &^orW  
} YX!iL6?~  
N"Z{5A  
2IK}vDsis  
public void setSFilePath(String value) %U/(|wodd  
{ %[GsD9_-  
sFilePath = value; ,>:U2%  
} 2_>N/Z4T  
{4l8}w  
_?nL+\'V  
public String getSFileName() [|v][Hwv  
{ \P[Y`LYL  
return sFileName; VMZMG$C  
} q9B$"n  
QL(n} {.%  
Lw1Yvtn  
public void setSFileName(String value) 82+r^t/.  
{ &<z1k-&!  
sFileName = value; 8C40%q..  
} hWjc<9  
-uS!\  
&bS,hbDt  
public int getNSplitter() <|HV. O/!  
{ h0EEpL|\  
return nSplitter; j/DzCcp7  
} )+#` CIv  
]U+LJOb  
juJklSD  
public void setNSplitter(int nCount) "MeVE#O  
{ ,CJWO bn3  
nSplitter = nCount; "69s)~  
} t5Sy V:fP  
} :@Pl pFK  
Q3'llOx  
+w`2kv  
/* w?L6!)oiz  
**Utility.java b1I]>\  
*/ #<fRE"v:Q  
package NetFox; p%ki>p )E|  
gt)I(  
g>%o #P7  
public class Utility { Xg6Jh``  
JtE M,tK  
G/E+L-N#`
 
public Utility() }CSDV9).S  
{  1~gnc|?  
l$KA)xbI  
<)Dj9' _J  
} FaAC&F@u  
MpT8" /.]A  
//线程睡眠 Q0sI(V#  
public static void sleep(int nSecond) hgG9m[?K  
{ M-VX;/&FR  
try{ "nynl'Ryk  
Thread.sleep(nSecond); 2k~l$p>CN!  
} SO/c}vnBB  
catch(Exception e) AYBns]!  
{ #^0R&) T
 
e.printStackTrace (); VD*6g%p  
} .^`{1%  
} ~12EQacOT  
9cbd~mM{  
//日志 [(i  
public static void log(String sMsg) ~ah~cwmpS  
{ B`)BZ,#p  
System.err.println(sMsg); >58YjLXb  
} dFxIF;C>/  
DeVv4D:}@  
),%%$G\  
public static void log(int sMsg) K8|r&`X0  
{ q>_.[+6  
System.err.println(sMsg); XS
B"{H>&  
} P8:dU(nlW  
} $S6`}3  
s[>,X#7 y  
7~h<$8Y(T  
/* C^Yb\N}S  
**TestMethod.java -m zIT4  
*/ +HpA:]#Y  
package NetFox; P= BZ+6DS  
U+jOTq8M  
&J]K3w1p  
public class TestMethod { Pbn*
_/H  
\!X8   
lN)C2
2  
public TestMethod() HVCe;eI  
{ ///xx/weblogic60b2_win.exe tKuwpT1Qc  
try{ "S]0  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !
PlEO 2at  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [85spub&}  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ($MlXBI  
fileFetch.start(); @gEUm_#HTs  
} qBQ?HLK-  
catch(Exception e){e.printStackTrace ();} G$"h&Xy1c  
a5^]20
Fa  
<NY^M!  
} H2 {+)  
u~:y\/Y6  
x_}:D *aI  
public static void main(String[] args) Mj3A5;#  
{ h2A <"w  
new TestMethod();  qA7>vi%  
} k"%~"9  
} K7B/s9/xs  
点击下载更多相关资料